2012-April-16 Tetra Tech Final Planning Document for Pine View Estates

Final Planning Document for theWastewater Treatment System and DrinkingWater System Assessment, Findings, andAlternatives for Pineview Estates

16 April 2012

Submitted to:

Bureau of Indian AffairsAttn: John F. Krause, Regional Environmental Scientist2600 North Central Avenue Suite 450Phoenix, AZ 85004

Prepared by:

Tetra Tech, Inc.4801 E. Washington St., Suite 260Phoenix, AZ 85034(602) 682-3300

Final Wastewater Treatment System and Drinking Water System Tetra Tech, Inc.Assessment, Findings and Alternatives for Pineview Estates April 2012

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TABLE OF CONTENTS

1.0 INTRODUCTION ................................................................................................................. 1

2.0 BACKGROUND ................................................................................................................... 12.1 REGULATORY BACKGROUND............................................................................................ 3

2.1.1 Underground Injection Permit....................................................................................... 32.1.2 Nevada Groundwater Discharge Permit......................................................................... 42.1.3 National Pollutant Discharge Elimination System Permit .............................................. 6

2.2 DRINKING WATER SYSTEM ................................................................................................ 62.3 WASTEWATER SYSTEM....................................................................................................... 7

2.3.1 Collection System......................................................................................................... 72.3.2 Treatment Systems........................................................................................................ 92.3.3 Disposal System.......................................................................................................... 10

3.0 ASSESSMENT .................................................................................................................... 113.1 DRINKING WATER SYSTEM .............................................................................................. 113.2 WASTEWATER TREATMENT SYSTEM............................................................................. 123.3 NITROGEN AND FECAL COLIFORM CONTAMINATION................................................ 143.4 DESIGN AND OPERATION & MAINTENANCE FACTORS............................................... 17

3.4.1 Design ........................................................................................................................ 173.4.2 Operation and Maintenance Deficiencies..................................................................... 18

4.0 ALTERNATIVES AND COST ESTIMATES...................................................................... 204.1 EXCLUDED ALTERNATIVES ............................................................................................. 20

4.1.1 Individual On-Site Sewage Disposal Systems.............................................................. 214.1.2 Land Application of Tertiary Treated Wastewater ....................................................... 214.1.3 Rapid Infiltration Basins for Effluent Disposal ............................................................ 214.1.4 Upgrade Existing Treatment System ........................................................................... 21

4.2 TREATMENT ALTERNATIVE 1: INSTALL PACKAGED TREATMENT PLANT ............. 234.2.1 Headworks.................................................................................................................. 244.2.2 Packaged Treatment Equipment.................................................................................. 254.2.3 Disinfection ................................................................................................................ 26

4.3 TREATMENT ALTERNATIVE 2: AERO-MOD TREATMENT PLANT ............................. 274.4 DISPOSAL ALTERNATIVE 1: IMPROVE EXISTING LEACH FIELDS............................. 284.5 DISPOSAL ALTERNATIVE 2: DISCHARGE TO SURFACE WATER ................................ 29

5.0 CONCLUSIONS.................................................................................................................. 31

6.0 REFERENCES .................................................................................................................... 32

FIGURES

Figure 1: Project Location Map ............................................................................................................... 2Figure 2: Wastewater Inflows January 2007 to December 2008 ............................................................... 8Figure 3: Wastewater Inflows May 2010 to February 2011 ...................................................................... 9Figure 4: Fecal Coliform Data for Monitoring Wells.............................................................................. 15Figure 5: Total Nitrogen Data for Monitoring Wells .............................................................................. 16Figure 6: Leach Field B Slope Issue....................................................................................................... 18Figure 7: Treatment System Media and Media Sieves ............................................................................ 22Figure 8: Example of a Two Train Packaged Treatment Plant ................................................................ 25Figure 9: SEQUOX Configuration Schematic........................................................................................ 27


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TABLE OF CONTENTS (Continued)

TABLES

Table 1: UIC Permit Effluent Concentration Limits ................................................................................ 4Table 2: UIC Monthly Injection Well Sampling Requirements................................................................ 4Table 3: UIC Monthly Monitoring Well Sampling Requirements............................................................ 4Table 4: Wastewater Treatment System Effluent Limits........................................................................... 5Table 5: Monitoring Well Sampling Requirements ................................................................................. 6Table 6: Influent and Effluent Wastewater Characteristics for Area A................................................... 13Table 7: Influent and Effluent Wastewater Characteristics for Area B................................................... 13Table 8: Percent Removal for Treatment Area A and B......................................................................... 13Table 9: Monitoring Well Groundwater MCLs ..................................................................................... 14Table 10: 2003 Leach Field Design Assumptions.................................................................................. 17Table 11: Existing Treatment System Retrofit Costs .............................................................................. 23Table 12: Recommended Design Criteria............................................................................................... 24Table 13: Treatment Alternative 1 Annual O&M Costs.......................................................................... 26Table 14: Treatment Alternative 2 Annual O&M Costs.......................................................................... 28Table 15: Required Leach Field Size..................................................................................................... 29Table 16: Disposal Alternative 1 Annual O&M Costs ............................................................................ 29Table 17: Disposal Alternative 2 Annual O&M Costs ............................................................................ 30

APPENDICES

Appendix A Tetra Tech 2012 Site Visit Wastewater System PhotosAppendix B 2004 EPA Wastewater System Installation PhotosAppendix C Existing System and Proposed Alternatives MapsAppendix D Wastewater Alternative ROM CostsAppendix E Report Presentation Meeting Minutes and Comment Response Spreadsheet


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1.0 INTRODUCTION

Tetra Tech developed this Planning Document for the Wastewater Treatment System and Drinking WaterSystem Assessment, Findings, and Alternatives project at the Pineview Estates development. Thisdocument includes pertinent site background and system assessment information; describes the nature andcause of elevated nitrogen and bacteria in the groundwater; and provides two recommended systemimprovement alternatives and costs associated with each alternative to correct system deficiencies. Thegoal of this Planning Document is to provide a cost effective solution to remedy the wastewater system atPineview Estates and achieve regulatory compliance.

In September 2004, the United States Environmental Protection Agency (US EPA) issued anUnderground Injection Control (UIC) permit authorizing wastewater injection at two disposal fieldswithin the subdivision boundary. Since that time, the US EPA has issued two Notice of Violation (NOV)letters and one administrative penalty order to the land owner, subdivision developer, and Home OwnersAssociation (HOA) for unauthorized underground injection activities at the Pineview Estates subdivision.The latest NOV letter, dated 5 January 2011, stated that groundwater quality data from monitoring wellsadjacent to two on-site wastewater disposal fields exceeded Safe Drinking Water Act (SDWA) MaximumContaminant Level (MCL) standards for nitrates and fecal coliform (US EPA 2011a). The Bureau of

Indian Affairs (BIA) currently holds in trust for the Indian allottee the land on which PineviewEstates is located and has elected to fund this assessment and alternatives recommendation report forthe wastewater disposal system at Pineview Estates.

The groundwater data from adjacent monitoring wells demonstrate that the subdivision’s on-sitewastewater treatment and disposal system is not functioning effectively. The levels of nitrogen and fecalcoliform bacteria, which are indicative of wastewater contamination, have been found in the monitoringwells adjacent to the disposal fields. Elevated concentrations of nitrogen and pathogens pose a risk togroundwater resources immediately underlying and in the vicinity of the subdivision and violate injectionstandards set by the SDWA and conditions required by Pineview Estates’ UIC Class V Injection Wellpermit (US EPA 2011b). Tetra Tech has found that the wastewater treatment system is not performing asintended and the disposal fields do not have adequate capacity to manage wastewater flow rates from thecommunity. The proposed engineering solutions presented in this report outline capital and operation andmaintenance (O&M) upgrades necessary to improve the effluent quality of the wastewater treatmentsystem and wastewater disposal methodology. These actions are recommended to limit future subsurfacecontamination so that the groundwater and subsequent drinking water supply will not be affected.

Section 2.0 of this report contains background information regarding Pineview Estates and applicableregulations. Section 3.0 provides an infrastructure assessment; describes the nature and extent of nitrogenand pathogen contamination in groundwater; and discusses original wastewater system design and O&Mfactors that are affecting system performance. Section 4.0 provides descriptions, conceptual plans, andrough order of magnitude (ROM) cost estimates for the proposed engineering solutions to remedy thewastewater system deficiencies. Section 5.0 summarizes the findings and provides a recommendedsolution. Section 6.0 provides applicable references to this report.

2.0 BACKGROUND

Pineview Estates is a residential development located approximately 5 miles southeast of Gardnerville,Nevada. Figure 1 shows the location map for the Pineview Estates project site. The subdivision is a 63acre plot of land directly adjacent to State Highway 395 that includes 211 residential lots, of which 20 lotsremain undeveloped and 20 lots are currently vacated (Robinson 2012). The total number of lots atPineview Estates has fluctuated as the community has expanded.


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Figure 1: Project Location Map


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The majority of homes are occupied by one or two individuals. The following text provides backgroundon the drinking water and wastewater systems and applicable regulations.

2.1 REGULATORY BACKGROUND

The regulations regarding the safe operation and function of the drinking water and wastewater systems atPineview Estates is currently under the jurisdiction of the US EPA, who have issued a UIC permit for the

Pineview Estates wastewater system. The existing system is located on a public domain allotment heldin trust on behalf of an Indian Landowner and is therefore out of the jurisdiction of local or Stateregulators. However, the BIA has requested that Tetra Tech develop two wastewater system alternativesas part of this project; one that complies with federal UIC requirements and one that complies withapplicable local or State of Nevada regulations. For this reason, Tetra Tech has also provided adiscussion of State regulations applicable to Pineview Estates.

Pineview Estates is located in Douglas County, Nevada. The Douglas County Building Departmentexplained that they have jurisdiction over small scale conventional on-site sewage disposal systems thatare not engineered. However, for larger scale systems such as the community treatment system atPineview Estates, Douglas County defers regulatory jurisdiction to the State (Nunes 2012). For systemstreating wastewater flow rates greater than 15,000 gallons per day, the NDEP Bureau of Water PollutionControl (BWPC) requires the operator to meet the requirements of a Nevada Groundwater DischargePermit and to be designed per NDEP wastewater treatment and disposal design guidance (Lanza 2012).

The following paragraphs explain both the existing US EPA regulatory requirements for the site andapplicable NDEP regulatory requirements for permitting and operating the Pineview Estates wastewatersystem.

2.1.1 Underground Injection Permit

The US EPA UIC permit defines wastewater effluent disposal limitations, monitoring and reportingrequirements, and operation and maintenance practices to ensure the safe operation of the sewage disposalsystem and protection of Waters of the United States (US).

Pineview Estates land owner (Mr. Leon Mark Kizer) and system operator (PTP, Inc.) were issued a UICPermit No. NV50400001 in September of 2004 for the injection of treated wastewater below the groundsurface at two wastewater disposal fields (leach field A and leach field B). By issuing this UIC permit, theUS EPA approved injection wells (leach field A and leach field B), treatment systems, and leach fieldsizing calculations for managing wastewater at Pineview Estates pending that the owner and operatormeets all permit requirements.

The UIC permit provides requirements for the location and setbacks from the wastewater disposal fieldsat Pineview Estates. In order to protect public health and to adequately characterize the impact ofinjection wells on groundwater quality, the permit requires four monitoring wells at each disposal field.In order to prevent the migration of injected fluids into an underground source of drinking water and toadequately characterize the injectate, the permitted operator is required to install and maintain monitoringand sampling ports at several locations within the treatment and disposal system.

The UIC permit monitoring requirements include sampling between the advanced treatment system andthe dosing units on a monthly basis to meet the effluent concentrations shown in Table 1.


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Table 1: UIC Permit Effluent Concentration Limits

ConstituentMaximum

Concentration (mg/L)

Five-Day Biochemical Oxygen Demand (BOD5) 25

Total Suspended Solids (TSS) 25

Nitrate-N 15

The Pineview Estates UIC permit limits the wastewater discharge volume for leach field A to 10,400gallons per day and for leach field B to 33,600 gallons per day. The permit also requires the developmentof a well maintenance plan and the execution of annual maintenance inspections.

The permit requires the development of a sampling plan that includes monthly monitoring well andinjection well sampling analysis. The monthly sampling must be carried out using the constituents andmethods shown in Table 2 and Table 3. Table 2 outlines the injection well sampling requirement atPineview Estates which is to be performed at the effluent of each of the treatment systems prior todisposal into the leach fields. Table 3 provides the monthly sampling requirements for monitoring wellssurrounding the leach field and provides a snapshot of groundwater quality surrounding the leach field.

Table 2: UIC Monthly Injection Well Sampling Requirements

Constituent Method

BOD5 Standard Method 5210B

Total Nitrogen Kjeldhal (TKN) Standard Method 4500C

TSS Standard Method 2540D

Nitrate-Nitrogen US EPA Method 353

Volatile Organic Compounds (VOC) US EPA SW-846 Method 8260

Table 3: UIC Monthly Monitoring Well Sampling Requirements

Constituent Method

Nitrate-N US EPA Method 353

Fecal Coliform Standard Method 9221

Coliphage Male-Specific, US EPA Method 1602

As part of the UIC permit, the US EPA requires monthly reporting of all maintenance activity outlined inthe approved Maintenance Plan and submittal of results from injection well and monitoring wellsampling. The US EPA also requires annual submittal of a comprehensive Annual MaintenanceInspection and a separate report detailing septic tank inspections on the first, third, and fifth years ofoperation. In addition, the results of the Annual Maintenance Inspection and sampling results must bemade available to the residents of Pineview Estates.

2.1.2 Nevada Groundwater Discharge Permit

The BIA has requested that Tetra Tech investigate State and local requirements for a communitywastewater treatment and disposal system. As discussed previously, the Douglas County BuildingDepartment confirmed that the County does not have jurisdiction over a large engineered wastewater


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treatment system like the one at Pineview Estates. The County defers to NDEP when the system is largerthan a conventional individual on-site sewage disposal system (OSDS) for a single family dwelling.

The NDEP BWPC would require the system operator to apply for a Groundwater Discharge permit.Systems injecting less than 15,000 gallons per day of sanitary waste are considered OSDS type systemsand would be permitted through the OSDS General Permit GNEVOSDS09 instead of as a groundwaterdischarge. The system at Pineview Estates is designed with a daily capacity of approximately 45,000gallons which exceeds the eligibility criteria of the OSDS General Permit and would require permittingthrough the Groundwater Discharge Permitting Program. In addition, since this is an existing systemalready permitted by the US EPA UIC program, it is likely that many permit requirements will simplytransfer to a NDEP Groundwater Discharge Permit. Given that the system has known functional issues,NDEP may impose more stringent permit requirements if it were to become their jurisdiction (Lanza2012).

The objective of the NDEP Groundwater Discharge Permit is to control and reduce pollution of Waters ofthe State from domestic sewage related to commercial activities. Through the use of the NDEPregulations and good engineering practices, all wastewater treatment and disposal systems shall bedesigned, constructed, operated and maintained to minimize impacts to ground water and protect publichealth (NDEP 2009).

The BDEP categorizes treatment system and sampling requirements as follows:

Category 1 - effluent from a standard septic tank with no mechanical/aerobic systems or norecirculating system.

Category 2 – effluent from a mechanical/aerobic system, multiple-pass filtration system (i.e.recirculating sand filters, recirculating textile filters, recirculating foam filters), single pass bedfilters (i.e. sand filters, peat filters).

Category 3 – effluent from a denitrification system, regardless of disposal method.

The treatment system at Pineview Estates is currently considered a Category 3 treatment system by theNDEP due to the denitrification process within the existing treatment tanks. The NDEP groundwaterdischarge permit requires operators of Category 3 denitrification treatment systems to treat to the effluentlimits shown in Table 4. If the treatment system did not contain a denitrification component, it would beconsidered a Category 2 treatment system and held to the same requirements as Table 4, without the TotalNitrogen requirement.

Table 4: Wastewater Treatment System Effluent Limits

Constituent Discharge Limit (mg/L)

BOD5 30

TSS 30

Total Oil and Grease < 20

Total Nitrogen 20

The NDEP Groundwater Discharge permit requires operators to provide sampling at monitoring wellsadjacent to the disposal field(s) on a quarterly basis. Sampling requirements for monitoring wells areshown in Table 5.


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Table 5: Monitoring Well Sampling Requirements

ConstituentMaximum Limit Detectedin Upper Aquifer (mg/L)

Frequency

Nitrate M & R Quarterly

Total Nitrogen < 10 Quarterly

E. Coli (CFU/100mL) M & R QuarterlyNote: M&R refers to the Monitoring & Reporting requirements determined by the NDEP.

The NDEP Groundwater Discharge permit would also require annual reporting on treatment system andmonitoring well water quality and overall system function.

2.1.3 National Pollutant Discharge Elimination System Permit

An alternative to the leach fields at Pineview Estates is to discharge wastewater from the treatmentsystems directly to surface waters. Discharges of pollutants to surface waters would require a NationalPollutant Discharge Elimination System (NPDES) permit. Under NPDES, all facilities which dischargepollutants from any point source into waters of the US are required to obtain a permit. The permitprovides two levels of control: technology-based limits (based on the ability of dischargers in the sameindustrial category to treat wastewater) and water quality-based limits (if technology-based limits are notsufficient to provide protection of the water body).

According to the NDEP, the effluent limits for the NPDES program would be the same as for the NDEPGroundwater Discharge Permit shown in Table 4, with the exception of a more stringent effluent limit onTotal Nitrogen of 10 milligrams per liter (Lanza 2012). A NPDES permit would be obtained through theUS EPA if the discharge point was within the Pineview Estates boundary, otherwise, the NDEP would bethe jurisdictional authority. Another scenario is if the allotted land held in trust is transferred tobecome fee land, in which case the NDEP would become the permitting authority.

The US EPA defines “waters of the US” as a navigable water or “non-navigable tributary to traditionalnavigable waters that is relatively permanent, meaning it contains water at least seasonally.” UnitedStates Geological Survey (USGS) quadrangle maps show blue lines for hydrography that is considered a“Water of the US.” The seasonal stream on the south side of Highway 395 from Pineview Estates wouldfit the description of a tributary to a traditional navigable water and be an appropriate discharge point forthe wastewater treatment system effluent. This means that the NPDES permit would be issued throughthe NDEP. A NPDES permit through NDEP would also set monitoring & reporting requirements andadministrative requirements for the discharge of wastewater effluent into the adjacent stream.

2.2 DRINKING WATER SYSTEM

The subdivision utilizes an on-site drinking water system, including a drinking water source well, pumphouse, distribution pipe network, and above ground storage tank. The drinking water system pumpsgroundwater from a well near the Pineview Estates entrance to an adjacent pump house. The well islocated approximately 75 feet from State Highway 395 and was originally installed in 1998. The well is480 feet in total depth and the static water level in the well at the time of installation was 29 feet belowground surface. A 2005 sanitary survey performed by the US EPA found that the water quality from theaquifer beneath Pineview Estates meets all primary and secondary drinking water standards andadditional treatment of the raw water was not necessary (US EPA 2005).

Well water is pumped to a 330,000 gallon bolted ground-level steel storage tank that was installed in 1999on the north side of the subdivision. The raw groundwater is not treated. The system was originally


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installed with a chlorination system, but the chlorination system was recently taken out of service since itwas not needed and was causing corrosion of the piping within the well house. The drinking watersystem is maintained by Certified Operator Ken Kanoff of SBP Utility Services, Inc. and PineviewEstates resident Jim Robinson. Mr. Kanoff acts as the system operator on a day to day basis and localresident Jim Robinson is available in the event of emergencies. The well is operated on a time clock andlocal operators perform checks of the system function at least one time per week. The drinking watersystem transmission and distribution mains were completed in 1999 and are made up of primarily 6-inchpolyvinyl chloride (PVC) pipes.

Exhibit 1 in Appendix C shows the site layout, including the drinking water system components andgeneral subdivision layout. Since previous electronic drawings were not available and a detailed sitesurvey was not part of this contract, the locations of the drinking water distribution lines wereapproximated from previous site plans developed by Lumos and Associates in 2003. Discussionregarding Tetra Tech’s assessment of the drinking water system is presented in Section 3.0.

2.3 WASTEWATER SYSTEM

Development of the wastewater system began in 1997 as the initial phases of Pineview Estates wereconstructed. Pineview Estates has constructed six phases of residential expansion thus far. The first threephases, and subsequently the oldest wastewater collection pipes, are located in the northwestern half ofthe property adjacent to Highway 395 and west of Ray May Way. These three phases were all originallydesigned to drain to leach field A. Leach field A was upgraded on several occasions to include additionalleach field lines to accommodate each phase of development. In March of 2004, the significant systemimprovements design was completed by Lumos and Associates to incorporate two sanitary lift stations,which provided the capability to pump all sanitary flows going to leach field A up to a new, larger leachfield B. The construction of the lift stations and treatment and disposal system at leach field B wascompleted in April of 2005. Discussion regarding Tetra Tech’s assessment of the wastewater system ispresented in Section 3.0. Photos from Tetra Tech’s wastewater system evaluation are presented inAppendix A. Photos from the 2004 installation of leach field B, obtained from the US EPA, are presentedin Appendix B.

Exhibit 2 in Appendix C shows the existing wastewater system at Pineview Estates. Since previouselectronic drawings of the wastewater system were not available and a detailed site survey was not part ofTetra Tech’s scope, the locations of the wastewater system components were approximated from previoussite plans developed by EXD Engineering in 2008 and verified with a handheld Global PositioningSystem (GPS) during Tetra Tech’s site visit performed on 7 February 2012. The wastewater systemoperator, Ken Kanoff, explained that the 2008 EXD Engineering drawings accurately reflect thewastewater system in its current state. Mr. Kanoff is the certified operator of the wastewater system; on aday to day basis and local resident Jim Robinson is available in the event of emergencies.

The wastewater system is made up of three components; collection, treatment, and disposal. These threewastewater system components are explained in the following text. Please refer to Exhibit 2 in AppendixC for a map of the Pineview Estates wastewater system.

2.3.1 Collection System

The septic tank at each individual home provides primary treatment of wastewater by settling of solidsand surface separation of oils and greases from the remaining wastewater. The effluent flows by gravityinto the primarily 4 and 6 inch diameter sanitary sewer collection system. At the time of Tetra Tech’s sitevisit, the system operator explained that none of the residences are required to pump their individualseptic tanks at a scheduled interval. The wastewater in the collection system upstream of treatment


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systems A1 and A2 flows into two lift stations, giving the operator the option to divert wastewater flowsinto treatment systems A1 or A2 or to pump it to the treatment system B. These two lift stations wereadded in 2005 and have been frequently used recently due to the groundwater quality results from leachfields A Monitoring Wells (MW). The two lift stations at A1 and A2 convey wastewater flows in a 4 inchdiameter polyvinyl chloride (PVC) force main. Two additional lift stations have been installed uphillfrom leach field A (shown as LS-B1 and LS-B2 in Exhibit 2 in Appendix C). All sanitary flows intoleach field B must be pumped from either LS-B1 or LS-B2. The lift stations are approximately 20 feetdeep. The lift stations convey wastewater to a settling tank within the fenced treatment system areaadjacent to leach field B.

Flow meter data was collected intermittently at treatment systems A1, A2, and B from 2006 to 2011. Theflow meter at treatment system A2 is frequently offline and seems to have recurring maintenanceproblems; therefore, A2 flow rates have only been recorded twice since installation in 2005. Flow meterresults for systems A1 and B are reported monthly from January 2007 to December 2008 and again fromMay 2010 to February 2011. The results of these flow metering results and the combined total flow areshown in Figure 2 and Figure 3.

Figure 2: Wastewater Inflows January 2007 to December 2008

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Jan-07 Aug-07 Feb-08 Sep-08

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Figure 3: Wastewater Inflows May 2010 to February 2011

The wastewater inflow data in Figure 2 and Figure 3 show that the influent flow to treatment system A1 isconsistently greater than the design flow capacities of 9,000 gallons per day (gpd). Treatment system B isoperating within its design capacity throughout the entire sampling period. The combined average dailyflow for both systems was observed to be 27,850 gpd for the recorded time period.

2.3.2 Treatment Systems

The first treatment area A1 is located on the southwest side of the Pineview Estates development nearHighway 395 on an abandoned entrance to the subdivision. Treatment system A1 consists of oneMicroFAST treatment unit designed to treat 9,000 gpd with effluent sent to leach field A1 to the west.The design calculations approved in the US EPA UIC permit approve system A1 to treat 7,200 gpd. Atthe time of Tetra Tech’s site visit, treatment system A1 was not being used. Treatment system A2 islocated approximately 200 feet east of system A1. This site is similar to A1 in that it consists of oneMicroFAST treatment unit designed for 9,000 gpd. The design calculations approved in the US EPA UICpermit approve system A2 to treat 3,200 gpd. Treatment system A2 effluent is sent to leach field A2.The treatment unit at A2 was currently being loaded at or greater than the design capacity of 9,000 gpd(refer to Figure 2 and Figure 3). The third treatment system (treatment system B) is located to the east ofthe other two treatment areas along southeastern subdivision boundary. System B consists of onesediment tank, a distribution box, four MicroFAST treatment units designed for 9,000 gpd each, aneffluent distribution box, and six dosing tanks to send effluent to leach field B. The design calculationsapproved in the US EPA UIC permit approve system B to treat 33,400 gpd.

Treatment systems A1 and A2 consist of a 23’L x 9’W x 8’H Jensen precast concrete tank with a liquidvolume of 5,600 gallons. Each concrete tank has Bio-Microbes BioFAST media installed inside. The

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treatment units A1 and A2 do not have settling tanks for disposal system dosing tanks. Each treatmentunit is equipped with one 6.5 HP blower and outfitted with an 8-inch diameter PVC air vent.

Treatment system B includes four rectangular concrete treatment tanks (23’L x 9’W x 8’H) aligned inparallel. Each tank has Bio-Microbics BioFAST media installed inside. One rectangular concrete settlingtank which is approximately 4,000 gallons provides settling of solids prior to entering the treatment tanks.After the settling tank, a three foot diameter concrete distribution box collects wastewater from thesettling tank and distributes it to the four parallel concrete wastewater treatment tanks. Four 6.5 HPblowers are included with one blower dedicated to each concrete tank. A 3-ft diameter concretedistribution box collects outflows from all four treatment tanks and distributes it to the dosing tanks.Dosing Tanks consist of six rectangular concrete tanks in parallel (approximately 16’L x 6’W x 8’H).The system operator explained that the outlets of the dosing tanks have two valves which allow forcontrol of the effluent to each of the leach field B distribution lines.

2.3.3 Disposal System

Outflow from treatment systems A1 and A2 is gravity fed into leach field distribution lines immediatelywest of the treatment systems. Leach field A1 has twelve 4 inch perforated PVC pipes in paralleladjacent to two abandoned leach fields to the east. The distribution lines in the middle of leach field Awere abandoned when the lift station at treatment system A1 was installed. The distribution lines at thewesterly edge of leach field A1 are not in use. The system operator noted that even when they open thevalve to send effluent to this field, the water does not reach the leach field, leading the operator to believethat there is a leak in this leach field’s distribution line.

Leach field B distribution lines were designed as twelve independently operating leach field areas, eachcontrolled by valves at the treatment area above. The six leach areas on the northwest side are rarely usedsince effluent typically overflows immediately after entering these distribution lines. The remaining sixsoutheastern leach areas are most frequently used. However, they must be monitored for over-saturation.The system operator explained that the lower of the six areas are typically saturated, especially during thewet season. The majority of leach field lines at leach field A consist of 4 inch perforated PVC pipes and 6inch perforated PVC pipes at leach field B.


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3.0 ASSESSMENT

In the previous section, Tetra Tech has summarized wastewater and drinking water system documentationcollected during the site visit and information gathered during subsequent interviews with regulatoryagencies and operators. In this section, Tetra Tech has analyzed this information to assess the quality ofthe original system design and current system function. This assessment analyzes the followingcomponents:

Drinking water well design and operation; Wastewater treatment system design and operation; Nature and extent of nitrogen and fecal coliform contamination of groundwater; and Design and O&M factors causing unacceptable effluent releases

3.1 DRINKING WATER SYSTEM

The drinking water system at Pineview Estates has not had any major documented or observed problemssince its installation in 1999 and is currently in compliance with US EPA requirements. At the time ofTetra Tech’s site visit, the system operators explained that the system has been functioning properly andno major system outages have occurred since they began operating the system in 2007.

The US EPA sanitary survey report in 2005 found 12 drinking water system deficiencies. The first 8deficiencies represent Health Risk Priority 2, or items that present a critical system defect, criticaloperational defect, or potential health hazard (US EPA 2005).

1. Replacement of the water storage tank vent and appurtenances;2. Development of a coliform site sampling plan and submittal to the EPA;3. Installation of a building or security fence surrounding the well location;4. Installation of a security fence surrounding the water storage tank;5. Installation of a locking mechanism on the water tank access hatch;6. Development of an Operation and Maintenance Manual (OMM);7. Create a spare parts kit for the chlorination device;8. Raise operator awareness of system improvements (Operator has since been changed);

The following item is Health Risk Priority 3, or items similar to level 2 but deemed by the US EPA to be“not as significant” (US EPA 2005).

9. Provide system telemetry and alarms for low water tank level, failure of well pump, etc.;

The last three items are Health Risk Priority 4. These are items similar to level 3 but deemed by the USEPA to be infeasible to correct immediately due to high capital costs (US EPA 2005).

10. Install residential water meters for billing and water balance analysis;11. Install an emergency backup power supply; and12. Install an additional drinking water supply well to provide redundancy.

Of these 12 system deficiencies, Tetra Tech observed that all except for the last three (Health RiskPriority 4) have been completed since the 2005 US EPA report. To address deficiency number 8, TetraTech observed that Mr. Kanoff has an excellent understanding of the system improvements and performssimilar system maintenance on multiple systems in the western Nevada region. An additional changesince 2005 is the removal of the chlorination device at the well head due to consistent malfunction.


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Tetra Tech recommends that a chlorination device be provided at the well head in the event of a positivecoliform result in the drinking water system and that the last three deficiencies (numbers 10, 11, and 12)be addressed by the appropriate party. The 2005 US EPA sanitary survey recommends the installation ofa second well, backup power supply, and residential water meters in order to provide a more reliablesystem to deliver clean drinking water to each residence at Pineview Estates and provide a means forimplementing a usage-based utility fee instead of the flat rate currently charged to users.

In the event that Pineview Estates becomes fee lands instead of allotted lands, the drinking water systemwould be permitted by the State of Nevada in accordance with Nevada Administrative Code (NAC)Chapter 445A “Water Controls.” The NDEP Bureau of Safe Drinking Water (BSDW) would requirePineview Estates to undergo an application process similar to requesting approval for new public watersystem. The application process would include submittal and review of drinking water system as-builtdrawings, system hydraulic model, well pump test results, and a site visit by NDEP to examine thedrinking water system. Tetra Tech is unaware of an existing hydraulic model or as-built drawings for theexisting drinking water system at Pineview Estates so it not possible to evaluate compliance with currentNAC design and construction standards. However, the Engineering Department at NDEP explained thatgiven the size and rural location of Pineview Estates, the drinking water system would be required to havea second source well that meets fire flow and average daily demand flows and a backup power supply inorder to comply with state regulations (Balderson, 2012). In the event that the lands at Pineview Estatesbecome fee lands, additional engineering analysis would need to be completed in order to develop theapplication documents, including system drawings and hydraulic model, for the drinking water system atPineview Estates. It is estimated that this engineering analysis would cost $40,000.

3.2 WASTEWATER TREATMENT SYSTEM

Each of the MicroFAST treatment units includes a buried concrete tank with a liquid volume ofapproximately 5,600 gallons. Each of the units is equipped with BioFAST media which provides a fixedsurface to promote the growth of a biofilm for treatment. Each unit has a 6.5 HP blower that compressesambient air and forces air up through the center of the BioFAST media. The air forces the water upcausing the water to hit a plate which spreads the water out over the media and adds dissolved oxygen tothe water. The aerated zone is designed for nitrification (conversion of ammonia to nitrate) and organicoxidation (removal of BOD). The media and aerated zone is approximately 92% of the total tank volume.The MicroFAST system is also designed for denitrification (conversion of nitrate to nitrogen gas) whichis required for meeting the UIC permit total inorganic nitrogen limit of 15 mg/L.

The existing wastewater treatment system is not working as designed with respect to nitrogen removal ororganic removal. Table 6 and Table 7 summarize the influent and effluent characteristics of the treatmentunits in Area A and Area B respectively.

Table 8 summarizes the percent removal of BOD5, total suspended solids (TSS), and Total KjeldahlNitrogen (TKN). It should be noted that each of the individual homes in the subdivision has a septic tankwhose overflow goes to the collection system to be treated by the treatment units. For this reason theinfluent BOD and TSS concentrations are lower than typical domestic wastewater.


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Table 6: Influent and Effluent Wastewater Characteristics for Area A

Influent EffluentBOD5

(mg/L)TSS

(mg/L)TKN

(mg/L)BOD5

(mg/L)TSS

(mg/L)NH3

(mg/L)TKN

(mg/L)Avg. 41 25 25 44 28 17 26Max 90 50 53 98 52 34 52Min 15 16 7.5 14 6 1.6 5.5

St. Dev. 24 10 16 25 14 13 17# Points 10 10 11 10 10 10 11

Table 7: Influent and Effluent Wastewater Characteristics for Area B

Influent EffluentBOD5

(mg/L)TSS

(mg/L)TKN

(mg/L)BOD5

(mg/L)TSS

(mg/L)NH3

(mg/L)TKN

(mg/L)Avg. 127 80 50 40 19 36 48Max 180 410 74 67 28 54 65Min 73 26 22 22 5 24 34

St. Dev. 28 101 12 14 6 11 9# Points 13 13 14 13 12 11 14

Table 8: Percent Removal for Treatment Area A and B

Treatment Area A Treatment Area BBOD5 %Removal

TSS %Removal

TKN %Removal

BOD5 %Removal

TSS %Removal

TKN %Removal

Avg. 5.5% 21% 8.4% 67% 61% 6.9%Max 26% 68% 36% 80% 97% 26%Min 0% 0% 0% 39% 12% 0%

St. Dev. 8.7% 25% 12% 13% 24% 9.0%# Points 10 10 11 13 12 14

As shown in the preceding tables, the treatment systems at both treatment area A and B are notperforming as designed and are not achieving sufficient organic, solids, or nitrogen removal. The BODshould be easily removed if there is sufficient biomass and sufficient air. Given that the average BODremoval percentage is poor, it is clear that one or both of these problems persist. The first possibility isthat there is not enough biomass in the system to provide adequate treatment. This was apparent to TetraTech during the site visit when looking into the top of one treatment unit and Tetra Tech personnel didnot see adequate biofilm on the media. The second possibility is that there is not enough oxygen beingprovided to the treatment system either through inadequate aeration capacity or inadequate air distributionthroughout the treatment tank. Tetra Tech evaluated the aeration capacity of the blowers and determinedthat there is sufficient aeration capacity using one 6.5 HP blower per treatment unit. While there isenough power to supply adequate oxygen, Tetra Tech is concerned that the existing media is impactingthe ability to mix the tank and distribute oxygen equally throughout the tank. The fixed media dissipatesthe mixing currents created by the aeration system which creates anaerobic (unaerated) zones throughoutthe tank.

Tetra Tech analyzed the tank volume required for aeration and determined that there is sufficient aeratedtank volume to achieve BOD removal and nitrification. Even though there is adequate aeration volumeand aeration capacity, the aerated portion of the treatment process is not producing adequate treatment.


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One possible explanation is that the water does not flow through the media. If the water goes around themedia and not through the center of the media very little biofilm will develop in the center of the mediadue to a lack of nutrients; thus there will be a decrease in treatment efficiency. Insufficient biofilmindicates biomass deficiencies in the system leading to inadequate biological treatment even though thereis sufficient tank volume. When inadequate flow distribution through the media is coupled withinadequate mixing of oxygenated water through the media, insufficient treatment can occur such asdemonstrated at Pineview Estates.

When Tetra Tech analyzed the tank volume required it was determined that while there was adequateaerated tank volume, there was inadequate anoxic (unaerated) tank volume for denitrification. There islimited organic matter entering the treatment system due to the use of septic tanks at the homes. The rateof denitrification is greatly limited when there is insufficient organic matter which leads to a larger tankvolume required. In most domestic wastewater facilities, the anoxic tank is 20 to 25% of the total tankvolume while the Pineview Estates system currently has an anoxic tank volume of 8%. Based on thelimited organic matter entering the treatment system, Tetra Tech recommends an anoxic tank volume of50% of the total tank volume. The denitrification performance of the Pineview Estates treatment systemcannot be evaluated at this time because the nitrification performance has failed to produce nitrate to bedenitrified.

Based on Tetra Tech’s assessment of the current treatment facility, it is our determination that the systemis not capable of complying with the required permit effluent quality without significant modifications.

3.3 NITROGEN AND FECAL COLIFORM CONTAMINATION

Both leach field A and leach field B have four monitoring wells surrounding the disposal fields, as shownin Exhibit 2 in Appendix C. These eight monitoring wells were installed at a depth of approximately 50feet below ground surface, as verified by well driller’s reports.

Leach field A was constructed from 1999 to 2005 and leach field B was constructed in 2005. Monitoringwell data has been collected since June of 2005 by two separate groups; Quicksilver Consulting Chemistsand current system operator, Ken Kanoff, of SBP Utility Systems, who uses Western EnvironmentalTechnology Laboratory to perform analytical testing. Due to the unknown reliability of data collectedunder previous system operator and testing labs, Tetra Tech focused on monitoring well sampling resultsprovided by the current system operator. It should be noted that monitoring wells MW A1 and MW B1have never been sampled since the wells are consistently dry.

Sampling results for Total Nitrogen and Fecal Coliform were provided to Tetra Tech for the period ofOctober 2009 to March 2011. All Fecal Coliform results are presented as Coliform Units (CFU) per 100milliliters (mL) of sample water. The laboratory testing limit and US EPA Drinking Water MaximumConcentration Limit (MCL) for both constituents are shown in Table 9. The water quality sampling datafor each leach field system are shown in Figure 4 and Figure 5.

Table 9: Monitoring Well Groundwater MCLs

Constituent Sampling Limit (mg/L) MCL (mg/L)

Fecal Coliform 2 CFU/100 mL 0 CFU/100 mL

Total Nitrogen 0.2 10


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It should be noted that two data points for Fecal Coliform in MW B2 for the 16 November 2010 and 13December 2010 sampling events were not included in the analysis as they exceeded 240 CFUs per 100mL sample and made it difficult to graphically represent the remaining results.

In addition, the data in the figures assume a value of zero for monitoring wells where the results werebelow the testing limit for that constituent. Therefore, it is possible that the result is not actually a zerovalue because it is lower than the detection limit but greater than zero. MW B3 only had one data pointfor Total Nitrogen since this well typically only has a few inches of water in the bottom of the wellaccording to the system operator.

Figure 4: Fecal Coliform Data for Monitoring Wells

Fecal Coliform results from leach field A show that MW A2, MW A3, and MW A4 were out ofcompliance for approximately 20 percent of the sampling period with CFU counts ranging from 2 to 38.The 38 CFU result occurred at MW A2 which is immediately down gradient of leach field A2.Groundwater flow in this area is in a southwesterly direction. The high result is most likely caused by thecombination of groundwater flow direction, infiltration of wastewater from leach field A with high FecalColiform counts, and the close proximity of MW A2 to the leach field. MW A1 has been dry sinceinstallation in 2005 and therefore, was never sampled.

Fecal Coliform results for leach field B show that MW B2 and MW B4, which are both in close proximityand directly down gradient of leach field B, have produced Fecal Coliform counts that are above the MCLfor approximately 50 percent of the sampling events since 2009 with CFU counts ranging from 2 to 26.MW B1 has never been sampled since it is always dry and MW B3 was only sampled twice but did notproduce CFU counts above 2. It is clear that wastewater entering leach field B is rich in Fecal Coliformand the short distance between MW B2 and MW B4 are resulting in high fecal coliform values at bothwells.

0

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MW A3

MW A4

MW B2

MW B4

MCL

DATE

FEC

AL

CO

LIFO

RM

(CFU

/10

0m

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Figure 5: Total Nitrogen Data for Monitoring Wells

Total Nitrogen results for leach field A show that MW A2 and MW A3 are above the MCL approximately92 percent of the sampling period, while MW A4 results are above the MCL approximately 8 percent ofthe sampling period. MW A2 and MW A3 are within 15 horizontal feet of the abandoned leach field linesto the east of leach field A2. It is likely that Nitrogen rich wastewater from these abandoned lines iscontaminating MW A2 which is directly down gradient of the lines. MW A3 is up-gradient of theabandoned leach field lines, but is directly in the path of two leach field distribution lines for leach fieldA1 and the adjacent abandoned leach field. It is most likely that a leak in either the abandoned orcurrently used distribution line is causing the contamination at MW A3. Total Nitrogen results for leachfield B show lower levels than leach field A and only one sampling result in MW B2 on 15 December2009 that was above the MCL for Total Nitrogen. The better results at leach field B MWs may be due tothe additional treatment components a treatment system B, including the settling tank and dosing tanks.Although the MW results are typically in compliance at leach field B, treatment system B effluentsampling results shown in Table 6 still show that effluent quality is not meeting regulatory requirements.

The sampling results show that effluent from treatment systems A1 and A2 entering leach field A iscontaminating the surrounding soils with Fecal Coliform and Nitrogen, posing a health risk to the aquiferbeneath Pineview Estates. In addition, Tetra Tech believes that a potential leak exists within the leachfield A1 distribution line or adjacent abandoned leach field line. The sampling results also show thatwastewater effluent from treatment system B entering leach field B is impacting the surrounding soilswith levels of Fecal Coliform above permit requirements, posing a health risk to the aquifer beneathPineview Estates.

0

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35

MW A2

MW A3

MW A4

MW B2

MW B3

MW B4

MCL

TOTA

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ITR

OG

EN(m

g/L)


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3.4 DESIGN AND OPERATION & MAINTENANCE FACTORS

Tetra Tech performed a review of design documents and performed interviews of system operators for thewastewater disposal system at Pineview Estates. The following paragraphs present a discussion of designand O&M deficiencies found during the assessment.

3.4.1 Design

The following system design deficiencies have been identified:

1. Soil percolation rates were overestimated at leach field A.

2. Wastewater inflow at leach field A was underestimated.

3. The overall terrain slope of leach field B is causing system overflows.

The original wastewater system design was performed in accordance with applicable State and federalregulations. Table 10 outlines Lumos and Associates’ design assumptions for each leach field (Lumosand Associates 2003).

Table 10: 2003 Leach Field Design Assumptions

Leach Field A1 Leach Field A2 Leach Field B

Criteria Design Value Design Value Design ValueResidences Serviced 36 16 167Design Percolation Rate (min/in) 22 22 60

Household Occupancy 1 (people) 2.59 2.59 2.59

Average Daily Wastewater Demand 1 (gal/d/p) 60 60 60

Average Daily Wastewater Inflow (gal/d) 7,200 3,200 33,400Treatment System Capacity (gal/d) 9,000 9,000 36,000Safety Factor 1.3 1.3 1.3Land Application Rate (gal/d/SF) 1.067 1.067 0.647

Maximum Effective Trench Depth 2 (feet) 5 5 4Length of Absorbtion Trench (feet) 675 300 6,4681 Source: US EPA Onsite Wastewater Treatment Systems Manual2 Source: Nevada Administrative Code (NAC) 444:8354

On-site percolation testing at leach field A was performed in October and December of 2003 by Lumosand Associates. The percolation test results ranged from 30 to 60 minutes per inch; however, a designpercolation rate of 22 minutes per inch was selected for both leach field A1 and A2. Per NACrequirements, the design percolation rate must be the slowest infiltration rate observed during percolationtesting, which was 60 minutes per inch for the leach field A area. This over estimation of infiltration ratesreduces the required linear feet of leach field pipe, resulting in an undersized leach field system.

Wastewater demand per capita was estimated at 60 gallons per capita per day in the 2003 designcalculations. From combined system flow data in Figure 4 and 5 and occupancy numbers of 191 homeswith two people in each home, the daily demand per capita is closer to 90 gallons per person per day. Atthe time of issuing this document, leach field A1 is not currently being used, but maintenance recordsshow that A1 was used heavily and above its design capacity of 9,000 gpd for several years (see Figures 3and 4). Leach field A2 is currently being used to treat approximately 9,000 gpd according to the systemoperator. A review of existing leach field line plans show that leach field A1 has approximately 470 LF


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of perforated lines and leach field A2 has approximately 650 LF of perforated pipe. Both leach field A1and A2 should be re-designed to manage the design flow and using the appropriate infiltration rate of 60minutes per inch.

Leach field B was constructed on land with an average slope of 23 percent grade. During construction,the leach field was “shelved” for each of the 12 leach field areas to minimize slope of the leach fieldareas. The leach field lines were designed with a 1 percent slope along the length of the pipe, but eachleach field area still has an overall slope of 5.5 percent. Each leach field has a 12 inch drop from thelowest pipe of the upstream system to the highest pipe of the downstream system. Perforated pipes wereonly buried 12 inches per the original design. This means that effluent entering the upstream system has asignificant chance of day-lighting at the downstream toe of the leach field, as shown in Figure 6.

Figure 6: Leach Field B Slope Issue

3.4.2 Operation and Maintenance Deficiencies

Based on Tetra Tech’s review of design documents and field observation at the wastewater disposalsystem at Pineview Estates, the following system O&M deficiencies have been identified:

1. Individual septic tanks at each residence may cause backflow into homes.

2. Leach field A is in need of maintenance and repair.

3. Treatment system A2 does not have a functioning flow meter.

Each residence at Pineview Estates has an individual septic tank prior to wastewater discharging to thecommunity wastewater collection system. These individual septic tanks act as settling basins and reducethe solids loading at the wastewater treatment systems. However, the system operator notified Tetra Techthat he has not observed any homes removing solids from their individual septic tank during his contractwith Pineview Estates. Failure to pump these septic tanks can result in the overflow of solids into thewastewater system and backflow of wastewater into homes. According to system operators, a few tankshave been pumped after solids have built up enough to cause backflow into the residence. Solids enteringthe collection and treatment system put additional strain on the system and can cause system fouling orfailure. Tetra Tech recommends the development of a septic tank management program to ensure theremoval of solids on a schedule basis. A typical pumping schedule for a 1,000 gallon tank serving a 4person residence is every 3 years. Removing the septic tanks from the collection system would requirehigh capital cost of abandoning the septic tank, re-plumbing the wastewater pipe, and revegetation of the


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surrounding area for each home. It is estimated that this cost would be $3,000 to $5,000 per home, or$573,000 to $955,000 total for the 191 existing homes. Tetra Tech does not recommend removing thetanks from the wastewater system at this time and proposed alternatives in Section 4.0 are designedassuming the tanks remain in place.

Leach field A consists of 5 separately controlled leach fields, each consisting of varying pipe diameters,separation distances, and lengths. This is caused by multiple design and construction iterations performedon an as needed basis for Phases 1, 2, and 3 of development at Pineview Estates. The two leach fields inimmediately east of leach field A1 (see Exhibit 2 in Appendix C) have been abandoned for several years.The sewer that conveyed wastewater to these two systems was cutoff and redirected to the lift station attreatment system A1 when the lift station was constructed. It is suspected that the proximity of these twosystems to MW A2 and MW A3 is causing contamination of the monitoring wells and perhaps this wasthe reasoning behind abandoning the leach fields. In addition, it is suspected that distribution lines(abandoned and currently used) may have a leak adjacent to MW A3. This monitoring well is up-gradientof the leach field systems but is still showing high levels of Total Nitrogen. Therefore, it is suspected thatthe cause of contamination is a broken distribution line. In addition, system operators have noticed thatwastewater flows sent to leach field A1 from treatment system A1 never seem to make it down to leachfield A1, also reinforcing the hypothesis that there is a leak in the line feeding leach field A1. If leachfield A is intended to be used in the future, Tetra Tech recommends that the distribution lines be checkedfor leaks and the abandoned leach field lines are re-installed to add leach field capacity.

Wastewater flow meters allow the system operator to monitor wastewater inflow volumes for eachtreatment system and better understand system demands and treatment system performance. The flowmeter at treatment system A2 has not functioned properly since first installed in 2004. This has resultedin data gaps for wastewater demand on-site and unknown volumes of wastewater entering treatmentsystem A2. This may have resulted in over-loading of treatment system A2 causing high concentrationsof contaminants to enter the leach fields at A2. Tetra Tech recommends that a functioning flow meter beinstalled at system A2.


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4.0 ALTERNATIVES AND COST ESTIMATES

Tetra Tech has developed two treatment alternatives and two disposal alternatives for eliminating furthereffluent discharge in exceedence of UIC permit requirements. Tetra Tech’s scope was to develop onealternative that satisfies local and State requirements and an additional alternative that satisfies federalrequirements. However, the difference between federal, State, and local regulations for the design andoperation of a wastewater treatment plant and disposal system is not great enough to create a difference intreatment requirements and therefore treatment system costs. The costs for complying with State andfederal requirements will be similar. For this reason, either of the treatment alternatives can be paired witheither of the disposal alternatives to achieve federal and state regulatory compliance. Each of theproposed alternatives does not include upgrades to the drinking water system since this system iscurrently in compliance with US EPA requirements.

Treatment alternative 1 proposes demolishing the existing treatment systems and constructing a singlepackaged treatment plant. Treatment alternative 2 proposes demolishing the existing treatment plant andconstructing a new, customized wastewater treatment plant (WWTP) using an AeroMod design. TetraTech does not recommend an option that modifies the existing system. Tetra Tech has also developedtwo disposal alternatives to dispose of the treated wastewater. Disposal alternative 1 proposes improvingthe existing leach fields. Disposal alternative 2 proposes installing an effluent disposal pipe to dischargeinto an adjacent surface water stream. Each proposed alternative is designed to manage wastewater flowsresulting from full build-out of the subdivision, or 211 occupied homes.

When developing alternatives for upgrading the wastewater system at Pineview Estates, Tetra Tech hadseveral goals in mind. These goals are as follows:

Eliminate Groundwater Contamination Risk – each alternative will eliminate the risk of furthercontaminating the groundwater aquifer and drinking water well at Pineview Estates.

Achieve Regulatory Compliance – each alternative will produce effluent that meets federal andstate effluent discharge and monitoring well requirements.

Minimize Costs – each alternative will achieve regulatory compliance for the lowest possiblecapital and O&M costs.

Minimize Long Term Maintenance Requirements – each alternative will not be computer based orrequire daily attention from a highly trained operator but rather would be relatively self-sufficientand minimize operating and maintenance requirements.

Maximize System Longevity – each alternative will utilize technologies that are proven to functionwell in regional conditions which will increase the life of the system.

Minimize Noise and Odor – each alternative will consider the location of the treatment system inproximity to residences and will try to minimize operating noise and treatment system odors.

4.1 EXCLUDED ALTERNATIVES

Tetra Tech considered several wastewater treatment and disposal alternatives during the writing of thisreport, but chose not to pursue them for various reasons. The following text outlines each of thesealternatives and the decision process in excluding them from the recommended alternatives.


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4.1.1 Individual On-Site Sewage Disposal Systems

Tetra Tech considered the alternative of installing individual leach field systems at each household atPineview Estates. The majority of residences are already outfitted with septic tanks and the outflows ofthe septic tanks could be diverted from the collection system to a leach field located at each residentiallot.

Tetra Tech did not pursue this option due to the leach field size requirement and available area at eachresidence. The largest lots at Pineview Estates have approximately 3,000 square feet of “openspace”. Local regulations have a minimum area requirement of approximately 14,500 square feet for anOSDS served by a community water supply (no drinking water well located on the individual’sproperty). In addition, considering setback requirements for leach field systems, the available area ateach residential lot would be further reduced. For these reasons, Tetra Tech did not pursue individualOSDS at each residence.

4.1.2 Land Application of Tertiary Treated Wastewater

Tetra Tech considered the alternative of treating the wastewater to a higher (tertiary) standard whichallows for land application (essentially irrigation) of selected areas on-site. This would require additionalfiltration of the wastewater during the treatment process and therefore, higher capital costs, but long termcosts would be less for operating and maintaining the land application area.

Tetra Tech did not pursue this option due to the climate at Pineview Estates. The site is at approximately5,400 feet above sea level and receives an annual average of 19 inches of snowfall and low averagetemperatures during the months of November to April (WRCC 2012). Land application of effluent wateris not feasible during the winter months and therefore this alternative was not pursued.

4.1.3 Rapid Infiltration Basins for Effluent Disposal

Tetra Tech considered the alternative of replacing the existing leach field effluent disposal system withRapid Infiltration Basins (RIB). RIBs are permeable earthen basins, designed and operated to treat anddisperse municipal wastewater. RIBs are typically operated in conjunction with either a primarywastewater pond, or a primary and secondary wastewater pond system (MPCA 2005). Rapid infiltrationof wastewater is based on a relatively high rate of wastewater infiltration into the soil followed by rapidpercolation, either vertically or laterally away. The best soils for rapid infiltration are relatively coarsetextured, with moderate to rapid permeabilities (US EPA 1984). RIBs would have the added benefit ofhigh evaporation rates during summer months.

Tetra Tech did not pursue this option due to the high capital cost of removing the leach fields andconstructing RIBs that would essentially function as the leach field system. The site is still limited by lowinfiltration rates and the relative benefits of evaporation potential do not justify the high capital cost ofconstruction. NDEP design guidance for RIB systems require a minimum infiltration rate of 2 inches perhour but infiltration rates on-site are closer to 1 inch per hour (NDEP 1993). For these reasons, TetraTech decided that upgrading the existing leach field was more cost effective than constructing a new RIBsystem.

4.1.4 Upgrade Existing Treatment System

Tetra Tech evaluated the improvements required to upgrade the existing treatment system to satisfyregulatory requirements. First, additional anoxic volume would be required for denitrification. This tankwould have to be located upstream of the aerated tank in order to use the organic matter for denitrification


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before it is aerobically oxidized by bacteria in the aerated zone. However, there is no nitrate to denitrifybefore the aerobic tank, so a pumped recycle loop from the end of the aerated tank to the anoxic tank mustbe installed to return nitrate produced during nitrification (which occurs in the aerated tank). This systemwould require the installation of four new tanks of equal volume to the aerobic tanks upstream of theaerobic tanks along with at least 4 internal recycle submersible pumps.

In the aerated tanks, the media will need to be removed because it inhibits the flow through the tank andis ineffective at growing biomass. In place of the fixed media, floating carrier media should be installedto turn the aerated reactor to a moving bed bioreactor (MBBR). The biofilm will grow on the MBBRmedia which will be suspended in the wastewater which enhances the contact time between the biofilmand the wastewater. The MBBR media will eliminate the problems with mixing and oxygen distributionthroughout the tank. Aeration diffusers would need to be installed along the bottom of the tank to provideaeration and mixing. Media sieves will need to be installed to keep the media in the tank. Photos ofsimilar media and media sieves are shown Figure 7 below for clarity.

Figure 7: Treatment System Media and Media Sieves

One of the problems associated with an MBBR system is that media sieves have small openings whichare prone to plugging with solids. If an MBBR system were to be installed in the existing tanks, newheadworks with a mechanical fine screen (maximum opening of 4 mm) and grit removal system wouldalso need to be installed to remove debris and other solids at the head of the treatment plant. In additionto the headworks, a clarification tank would need to be installed to collect solids and biofilm that sloughsoff the media. The bacteria that slough off the media will need to be neutralized to prevent microbialcontamination in the leach fields.

The improvements that are required to existing system would include, a new headworks with mechanicalscreening and grit removal, new anoxic tanks, new aeration diffusers, new MBBR media and mediasieves, new clarification tanks, and a new chemical disinfection system. These improvements are costlyand are close to (or potentially more costly) than constructing a new treatment facility from ground up.

There are many benefits with designing and constructing a new treatment plant from the ground upinstead of retrofitting the existing facility. Water quality and flow meter data gathered since 2005 willallow the engineer to tailor the system capacity and treatment processes to the known constituentconcentrations and flow rates. The estimated cost of retrofitting the existing system is shown in Table 11.Considering the estimate cost for the retrofit is close to or more than construction of new facility, TetraTech recommends construction of a new facility.


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Table 11: Existing Treatment System Retrofit Costs

Item No Description Quant. Unit Unit Cost Total

1 Headworks Slab 25 CY $550 $13,750

2 Mechanical Screen, Washer/Compactor 1 EA $75,000 $75,000

3 Pre-Engineered Headworks Building 400 SF $120 $48,000

4 Anoxic Tanks 4 EA $15,000 $60,000

5 Aeration Diffusers 1 LS $25,000 $25,000

6 MBBR Media, Sieves and Equipment Package 4 EA $40,000 $160,000

7 Clarification Tanks 4 EA $20,000 $80,000

8 Disinfection System 1 EA $20,000 $20,000

9 Piping 1 LS $10,000 $10,000

10 Electrical, Instrumentation and Controls 1 LS $96,350 $96,350

11 Civil Works 1 EA $30,000 $30,000

Construction Subtotal $618,100

12 Profit (15%) $92,715

13 Design (8%) $49,448

14 Construction Oversight (8%) $49,448

15 Estimating Contingency (15%) $92,715

Total Construction Cost $902,000

4.2 TREATMENT ALTERNATIVE 1: INSTALL PACKAGED TREATMENTPLANT

The first considered alternative is to construct a new packaged treatment plant that is designed fornitrification and denitrification. This alternative will achieve compliance with treatment requirements,minimize the risk of further impacting groundwater, be cost effective, and minimize long term systemmaintenance. Exhibit 3 in Appendix C shows the conceptual layout of the treatment plant.

A WWTP is designed and permitted based on maximum month (MM) conditions; however, averageannual (AA) is the only data available at this time. Tetra Tech assumed that the MM to AA ratio was 1.2which is based on past experience for this size of treatment plant and similar communities. The flowprojections were based on an AA flow of 80 gallons per person per capita (assumed 211 homes build outat 2.59 people per home). Table 12 summarizes the design criteria recommended by Tetra Tech to beused during the design of the WWTP Improvements. The BOD5 concentration assumes the individualseptic tanks will remain in place.


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Table 12: Recommended Design Criteria

Parameter Units ValueQAA gpd 43,800QMM gpd 52,500

BOD5 Conc. mg/L 130BOD5 Loading MM lbs/day 59

TSS Conc. mg/L 80TSS Loading MM lbs/day 37

NH3:TKN ratio 0.75NH3 Conc. mg/L 38

NH3 Loading MM lbs/day 17

There are many manufacturers of packaged treatment plants that would be well suited for this application.A packaged treatment plant incorporates aeration tanks, clarifiers, and equipment required on a singleskid with capacities up to 150,000 gpd in a single train. The packaged treatment plant would be designedwith properly sized aeration tank to operate with on/off aeration for nitrification and denitrification. Fromthe aeration basins, the flow will be sent to the clarifiers where the suspended biomass will settle to bepumped back to the head of the aeration basin while the clean water flows from the plant. Mostmanufacturers can incorporate disinfection into the treatment system. A headworks facility with amechanical screen will be required; although a grit removal system is not required. It is not intended tothe packaged treatment plant to use MBBR, Integrated Fixed-Film Activated Sludge (IFAS), ormembrane bioreactors as the secondary treatment technology because there are additional headworksrequirements and a higher degree of operator experience required for these types of treatment systems.

For this alternative, it is envisioned that all wastewater be pumped to a single treatment plant site locatednear the current Treatment Area B. To maximize the distance of the WWTP from the nearest residence, itis recommended that the new WWTP be located directly south of the existing treatment area B as far aspossible away from the residential area. The collection system already allows for all of the wastewaterflow to be pumped to treatment area B.

4.2.1 Headworks

The pumped wastewater via the existing lift stations will be pumped to a new headworks facility forscreening. A mechanical screen with a maximum screen opening of 6 mm should be installed to removedebris and trash from wastewater. There are many types of mechanical screens that should be evaluatedduring the design. The screen should be equipped with a screenings washer and compactor. The washerand compactor equipment is designed to wash organic material from the screening back to the wastewaterto minimize odors. After washing, the screenings are compacted to produce a dried end product that canbe hauled to a landfill. It is not anticipated that grit removal will be required but this will have to beconfirmed during the detailed design. From the headworks, the wastewater will flow to the new packagedtreatment plant.

The new WWTP will be located relatively close to existing homes (approximately 250 ft); therefore, odorpotential is a major concern. The best mitigation against odors from the headworks is to construct anodor controlled building around the screening equipment. Odor control equipment for a relatively smallspace such as the headworks building could be accomplished using a ventilation system with carbonabsorption.


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The wastewater flow at Pineview Estates is entirely from residential homes. There is not any diurnal flowdata available; however, knowing the nature of the customer base, it can be assumed that there are twodiurnal peaks throughout the day, one in the morning when residents wake up and get ready for work, andone at night when people come home. The majority of the flow will occur during these two peaks;therefore, equalization of the diurnal flow is critical. The exact amount of equalization tank volumeshould be evaluated during the detailed design; however, the tank should be large enough to minimize thepeak flow to the secondary treatment system to 1.5 times the rated capacity.

4.2.2 Packaged Treatment Equipment

This alternative recommends the use of a two train packaged treatment plant that uses an on/off aerationcontrol strategy. An example of this type of treatment system is shown in Figure 8. The on/off aerationbasins uses an automatic blower control strategy to turn the air on and off for nitrification anddenitrification. When the air is on, organic matter will be oxidized and the ammonia will be nitrified toproduce nitrate. After a set amount of time, the blowers will be turned off. Once the residual dissolvedoxygen is consumed, the bacteria will use nitrate and denitrification (conversion of nitrate to nitrogen gas)will occur. The nitrogen gas produced from denitrification will dissipate out of the water into theatmosphere thus removing nitrogen from the water. After treatment is finished in the aeration tank, thewater will flow to the secondary clarifiers where the treated water overflows the clarifier and the settledsolids are returned to the head of the aeration tank.

Figure 8: Example of a Two Train Packaged Treatment Plant (Source: Hi-Tec Environmental)

There are several pieces of equipment that will be packaged with the treatment plant manufacturer. Eachtrain will require a mechanical mixer to maintain mixing without aeration. Each aerated zone should beequipped with aeration diffusers which will provide mixing and aeration. Air will be supplied to thediffusers through the use of blowers. The aeration system should have a dissolved oxygen probe tocontrol the speed of the blower to make sure enough, but not too much air is added. This control iscritical to minimize energy costs.

Following the aeration basins, the packaged treatment plant will include at least two secondary clarifiers.The secondary clarifiers will consist of preferably circular clarifiers with a mechanism to collect settledsludge at the bottom of each clarifier. The settled sludge will be pulled from the bottom of the clarifier


Page 26

and pumped back to the head of the aeration tank by the return activated sludge pumps. It isrecommended that non-clog centrifugal pumps be used for this service instead of air lift pumps whichmany packaged plant manufacturers typically incorporate. Centrifugal pumps offer superior controlcompared to air lift pumps. The sludge return system must also include a means of wasting sludge fromthe system. Wasting can be incorporated by either installing a separate pump or a use of a valve from thereturn sludge line. The only necessity for the wasting system is that a waste flow meter must be includedto measure the amount of sludge being wasted.

The wasted sludge must be pumped to an aerobic digester or an aerated sludge holding tank. These tankstypically are or at least can be incorporated into the design of a packaged treatment. The aerobicdigester/sludge holding tank must be aerated with aeration diffusers to minimize odor production. TetraTech recommends that Pineview Estates contract with a sludge hauling company (it can be a septicpumper) to periodically remove the sludge from the aerobic digesters/sludge holding tank. The sludgewill then be taken to a nearby wastewater treatment plant for disposal.

4.2.3 Disinfection

The final process at the WWTP would be disinfection. The disinfection process will kill residualpathogenic bacteria that are found in the clarifier effluent. There are two main types of disinfection usedwith packaged treatment plants. The first is the chemical disinfection typically with liquid sodiumhypochlorite (bleach) or tablets of calcium hypochlorite. Both chemical disinfection options are viable atPineview Estates and the detailed design should evaluate which option is most economical and easiest tomaintain. The second method of disinfection is through the use of concentrated ultraviolet (UV) light.UV disinfection requires a higher level of mechanical maintenance than chemical disinfection; althoughthe operators don’t have to monitor the level of chemicals on a daily basis. Given Pineview Estate’s rurallocation and limited mechanical maintenance capability Tetra Tech recommends the use of chemicaldisinfection.

After the treated water has been disinfected, it should meet permit requirements and could be discharged.Wastewater disposal options are discussed later in this report under Section 4.4 and Section 4.5. A RoughOrder of Magnitude (ROM) construction cost estimates for this alternative is shown in Appendix D. Theestimated total capital cost for this wastewater treatment alternative is $941,000. Annual O&Mrequirements would include effluent sampling of wastewater treatment plant effluent, removal of sludgefrom the WWTP, and weekly operation of the WWTP by a certified operator. The estimated annualO&M costs for this alternative are approximately $79,000 as shown in Table 13. The electricityrequirement and operation contract costs are expected to be similar to the existing treatment system atPineview Estates.

Table 13: Treatment Alternative 1 Annual O&M Costs


1 Electrical 261,502 kW-hr $0.08 $20,920

2 Sludge Removal 40 1000 gal $250 $10,000

3 Contract Operations Contract 1 LS $35,000 $35,000

O&M Subtotal $65,920


Total Annual Cost $79,000(1) Unit cost quoted from Summit Plumbing Company on March 12, 2012.


Page 27

4.3 TREATMENT ALTERNATIVE 2: AERO-MOD TREATMENT PLANT

Tetra Tech’s second treatment alternative is the construction of an Aero-Mod treatment plant. Aero-Modis an equipment manufacturer that uses a patented configuration and equipment for the activated sludgeprocess. Aero-Mod terms their plant configuration as a SEQUOX plant that consists of a selector mixingtank, an aerated nitrification stage, a sequencing aeration stage (on/off aeration), a clarifier, and anaerobic digester. All of the different process components use common wall construction to minimize costand footprint. Exhibit 3 in Appendix C shows the conceptual layout of the treatment plant. A schematicfigure of the SEQUOX configuration and a sample photograph of SEQUOX plant are provided in Figure9.

Figure 9: SEQUOX Configuration Schematic

The same design criteria as indicated in Table 12 were used to size the AeroMod system. This alternativeassumes that the individual septic tanks will remain in use. For the SEQUOX process, return activatedsludge (RAS) from the clarifiers mixes with the influent wastewater in the selector tank, sized forapproximately 30 minutes detention time. The mixed liquor (the combined RAS and wastewater) thenmoves to the 1st stage aeration tank where the contents are kept fully aerobic for complete BODdegradation and nitrification. Air is supplied by positive displacement blowers to fine bubble diffusersarranged along the wall of the aeration tank. Diffuser assemblies are designed to be individually takenout of service for periodic maintenance without taking the entire basin out service. Next, the mixed liquortravels under a baffle wall to the 2nd stage aeration tank, which is supplied with coarse bubble diffusers(arranged along the wall) and operated in an on/off aeration mode to create anoxic zones. Nitrate, formedin the 1st stage aeration tank, will be utilized in the denitrification process in the unaerated zones, reducingthe total nitrogen in the effluent.

The most unique aspect of the Aero-Mod system is the clarifier design called the ClarAtor. Mixed liquorfrom the 2nd stage aeration tank is distributed evenly throughout the bottom of the clarifier rather than inthe center of typical circular clarifier. Air lift pumps operated on timers take RAS from the bottom of theclarifier and return it back to the selector tank. Periodically, mixed liquor is wasted from the 1st stageaeration tank to an integrated aerobic digester by air lift pumps. The frequency and duration of wastingare controlled by timers.

The same headworks and disinfection configuration as described in treatment alternative 2 would berequired for this alternative. Also it is anticipated that sludge will be removed from the aerobic digestersand taken to a nearby wastewater treatment facility as described in treatment alternative 2.

A Rough Order of Magnitude (ROM) construction cost estimates for this alternative is shown inAppendix D. The estimated total capital cost for this wastewater treatment alternative is $991,000.


Page 28

Annual O&M requirements would include effluent sampling of wastewater treatment plant effluent,removal of sludge from the WWTP, and weekly operation of the WWTP by a certified operator. Theestimated annual O&M costs for this alternative are approximately $82,000, as shown in Table 14. Theelectricity requirement and operation contract costs are expected to be similar to the existing treatmentsystem at Pineview Estates.

Table 14: Treatment Alternative 2 Annual O&M Costs


1 Electrical 290,500 kW-hr $0.08 $23,240

2 Sludge Removal 40 1000 gal $250 $10,000

3 Contract Operations Contract 1 LS $35,000 $35,000



Total Annual Cost $82,000(1)

Unit cost quoted from Summit Plumbing Company on March 12, 2012.

4.4 DISPOSAL ALTERNATIVE 1: IMPROVE EXISTING LEACH FIELDS

The first disposal alternative is to improve the existing leach fields. Both of the existing leach fields areundersized for managing wastewater demand from Pineview Estates. This is a result of an undersizedleach field at leach field A and poorly sloped system at leach field B. Under this alternative, both leachfields would be updated. Leach field A would be enlarged to renew the abandoned leach lines andproperly size the distribution lines for the correct percolation rates. Leach field B would be expanded andcut into the hillside to provide a flatter slope, thus reducing the possibility of surface discharges andexpanding the area of potential infiltration. Exhibit 3 in Appendix C shows the conceptual layout of theleach field improvements.

Conceptual level design calculations show that the leach field would require an additional 4,000 linearfeet of leach field distribution lines on-site. Table 15 shows Tetra Tech’s preliminary design calculationsfor the proposed leach field. The daily wastewater demand per household was taken from the flow meterdata peak monthly demand from December of 2010.


Page 29

Table 15: Required Leach Field Size

All leach fields

Criteria Design Value

Residences Serviced 2111

Design Percolation Rate (min/in) 60 2

Design Application Rate 2 (gal/sq. foot) 0.6 3

Average Daily Wastewater Demand 1 (gal/d/house) 1634

Average Daily Wastewater Inflow (gal/d) 34,395

Safety Factor 1.5

Maximum Effective Trench Depth 3 (feet) 4

Length of Absorption Trench (feet) 10,7501 Assumes full build-out of all existing lots2 Source: Lumos and Associates Percolation Testing (2003)3 Source: Nevada Administrative Code (NAC) 444:83544 Source: On-site flow meter data

Leach field A currently has 1,000 linear feet of functioning leach field lines and leach field B has 7,200linear feet. The total length of existing leach field lines is approximately 8,220 and an additional 2,530linear feet would need to be added to the system to satisfy these design requirements. Leach field A hasthe potential to add approximately 800 linear feet if the abandoned leach fields are reconnected. Theadditional leach field capacity would have to be provided in the reserved leach field areas to the south andeast of leach field B. This would require additional percolation testing in these areas to determinepercolation rates. Tetra Tech also recommends that the existing leach field B distribution area be filledand raised in order to level out the leach field and promote vertical infiltration and minimize lateralinfiltration of effluent from the leach field.

A Rough Order of Magnitude (ROM) construction cost estimate for this alternative is shown in AppendixD. The estimated total capital cost for this wastewater disposal alternative is $363,000. Annual O&Mrequirements would include monthly effluent sampling at the monitoring wells, maintenance of the leachfield distribution system, and permit monitoring and reporting requirements. The estimated annual O&Mcosts for this alternative are approximately $20,400, as shown in Table 16.

Table 16: Disposal Alternative 1 Annual O&M Costs


1 Sampling & Reporting Contract 1 LS $15,000 $15,000

2 System Maintenance and Repair 1 LS $2,000 $2,000



Total Annual Cost $20,400

4.5 DISPOSAL ALTERNATIVE 2: DISCHARGE TO SURFACE WATER

The second disposal alternative is to construct an outfall pipeline from the WWTP and discharge theeffluent to the adjacent tributary to a water of the US. This alternative will achieve compliance withtreatment requirements, eliminate the risk of further contaminating groundwater, minimize long term


Page 30

system maintenance, and be cost effective. Exhibit 3 in Appendix C shows the conceptual layout of thedischarge pipe.

This alternative would require the installation of an outfall discharge pipe to convey treated effluent fromthe WWTP to the discharge point across Highway 395 and downstream of the existing residences on thesouth side of Highway 395. The section of the discharge pipe within the Nevada Department ofTransportation (NDOT) right-of-way would be permitted through NDOT for occupancy of a NDOT right-of-way for the installation of a utility and drainage feature. The NDOT occupancy permit applicationwould include design drawings and specifications, a traffic impact study, and a drainage impact report toshow that wastewater flows will not adversely impact the existing drainage features. The exact location ofthe discharge point would avoid adjacent private residences and discharge into the existing drainage swalealong Highway 395. This drainage swale turns towards the west and does not flow onto adjacent privateproperties.

The Carson River, the ultimate receiving water of the proposed treated effluent, has been identified as animpaired water by the State of Nevada and total maximum daily loads (TMDLs) have been establishedfor phosphorus, turbidity, and total suspended solids The Carson River TMDLs and water qualitystandards were reviewed as part of this evaluation and it is anticipated that the proposed wastewatertreatment system would produce treated effluent that meets these standards and could be permitted byNDEP without additional treatment requirements. To account for potential future changes in waterquality standards, Tetra Tech has included a contingency line item in the cost estimate.

This alternative would require approximately 3,100 linear feet of 8 inch PVC pipe. No pumping of theeffluent would be required. Final design calculations should be performed upon deciding the finalalignment of the effluent discharge pipe and treatment system elevation.

Since the permitted leach fields at Pineview Estates would no longer be used under this alternative, theproper closure actions would need to be performed in order to satisfy the UIC permit closurerequirements. Leach field closure requirements would include capping the upstream ends of the leachfield lines and abandoning in place.

A Rough Order of Magnitude (ROM) construction cost estimates for this alternative is shown inAppendix D. The estimated total capital cost for this wastewater disposal alternative is $317,000. AnnualO&M requirements would include effluent sampling at the discharge point to the Water of the US,maintenance of the discharge pipe from the treatment plant to the stream, and permit monitoring andreporting requirements. The estimated annual O&M costs for this alternative are approximately $26,400,as shown in Table 17.

Table 17: Disposal Alternative 2 Annual O&M Costs


1 Sampling & Reporting Contract 1 LS $20,000 $20,000

2 System Maintenance and Repair 1 LS $2,000 $2,000



Total Annual Cost $26,400


Page 31

5.0 CONCLUSIONS

This Planning Document for the Wastewater Treatment System and Drinking Water System Assessment,Findings, and Alternatives project at the Pineview Estates development provided an evaluation of thenature and cause of elevated nitrogen and bacteria in the groundwater. This report provided tworecommended system design alternatives to correct deficiencies within the wastewater treatment systemand ensure long term, compliant operation of the wastewater treatment system.

Tetra Tech found that the drinking water system was functioning properly and suggested system upgradesoutlined in the 2005 US EPA report had been executed with the exception of long term upgrades such ashousehold water meters, a backup electrical supply, and installation of a backup supply well. Tetra Techrecommends that these system upgrades are implemented as part of a long term drinking water systemmanagement plan. Tetra Tech also found that the drinking water disinfection unit has been taken out ofservice due to malfunction and corrosion. It is recommended that an appropriate disinfection unit beinstalled at the well pump house to provide disinfection of drinking water.

The wastewater treatment system at Pineview Estates is not functioning properly, causing nitrogen andpathogen rich wastewater effluent to be released to the adjacent leach field and subsequently to theadjacent monitoring wells and groundwater beneath Pineview Estates. In addition, the leach fields wereoriginally designed without adequate capacity to manage full build-out design flows and withoutconsideration of on-site percolation rates and terrain slope. Groundwater impacts observed in themonitoring wells can be attributed to improperly treated wastewater from the Pineview Estatessubdivision.

Tetra Tech proposes a twofold preferred alternative. The preferred alternative requires the installation of anew wastewater treatment system (treatment alternative 1) to ensure that wastewater effluent qualitymeets regulatory requirements and surface discharge of the effluent to an adjacent stream to eliminate thepossibility of further impact to groundwater (disposal alternative 2). This alternative will provide a lowmaintenance and effective long term solution for managing wastewater at Pineview Estates. Retrofittingthe existing treatment system was shown to be just as costly as a new system and with less certainty ofeffluent water quality. This alternative will require pursuit of a NPDES surface water discharge permit inorder to discharge the wastewater effluent to the adjacent stream. This disposal method will eliminate therisk of continuing to use the leach field disposal system which has shown limited infiltration capacity.Tetra Tech’s recommended solution will require $1,258,000 in capital costs to implement and anestimated $105,400 in annual O&M costs. The conceptual plans discussed in this report should be furtherinvestigated and completely designed prior to moving forward with construction of any of the proposedalternatives.

At the time this report was written, 171 of the 211 homes at Pineview Estates are occupied and 20 of thelots remain undeveloped. The existing wastewater treatment system is not able to properly treat anddispose of current wastewater flow rates and water quality. Further development and occupancy of thePineview Estates neighborhood will put additional burden on the wastewater treatment and disposalsystem, increasing the risk of negative impacts to the surrounding groundwater. To avoid these negativeimpacts, Tetra Tech highly recommends immediate action to correct the wastewater treatment systemdeficiencies with the preferred alternative outlined above. Pursuing the preferred alternative will requirefull design plans and specifications and coordination with the NDEP and NDOT to permit the surfacewater discharge. In addition to upgrading the wastewater treatment system, Tetra Tech recommendsconsistent maintenance of the individual septic tanks. Septic tanks that are full of sludge increase the riskof backflows into the residence. The current treatment system is not designed to manage solids buttreatment alternatives proposed in this report are designed to manage solids; therefore, the septic tankscan remain in place but should be properly maintained by individual homeowners.


Page 32

6.0 REFERENCES

Balderson, James. 2012. Nevada Department of Environmental Protection (NDEP). Personalcommunication. Applicable NDEP regulations for Pineview Estates Drinking Water System. April.

Lanza, Alex. 2012. Nevada Department of Environmental Protection (NDEP). Personal communication.Applicable NDEP regulations for Pineview Estates Wastewater Treatment and Disposal System.March.

Lumos and Associates, 2003. Pineview Estates Subdivision On-Site Regional Effluent Disposal Area(design calculations). 9 December 2003.

Minnesota Pollution Control Agency (MPCA), 2005. Guidance and Submittal Requirements for RapidInfiltration Basin Wastewater Treatment Systems. March.

Nevada Department of Environmental Protection (NDEP), 1993. Guidance document for an applicationfor rapid infiltration basins. WTS-3. March 30.

Nevada Department of Environmental Protection (NDEP), 2009. Onsite Sewage Disposal SystemGeneral Permit. Bureau of Water Pollution Control. 16 January 2009.

Nunes, Valerie. 2012. Douglas County Building Department. Personal communication. DouglasCounty jurisdiction over Pineview Estates wastewater treatment and disposal system. March 13.

Robinson, Jim. 2012. Pineview Estates wastewater system operator. Personal Communication regarding:occupancy of Pineview Estates subdivision. March 21.

United States Department of the Interior (USDOI), 2011. Notice of Violation Follow Up Letter. Bureauof Indian Affairs, Western Regional Office. Letter dated March 31, 2011.

United States Environmental Protection Agency Region IX (US EPA), 2005. Sanitary Survey Report forPineview Estates. Conducted by The Cadmus Group on 14 December 2004. Letter dated 3 May2005.

United States Environmental Protection Agency (US EPA), 1984. Process Design Manual for LandTreatment of Municipal Wastewater Supplement on Rapid Infiltration and Overland Flow. EPA625/1-81-013a. p. 1.

United States Environmental Protection Agency Region IX (US EPA), 2011a. Notice of Violation:Unauthorized Underground Injection Activities at Pineview Estates Subdivision. Letter dated 5January 2011.

United States Environmental Protection Agency Region IX (US EPA), 2011b. Duty to ProvideInformation: Unauthorized Underground Injection Activities at Pineview Estates Subdivision. Letterdated 15 February 2011.

Western Regional Climate Center (WRCC), 2012. Climate data for Minden, Nevada. Station ID: 265191.Period of Record: 1/ 1/1928 to 12/31/2005. Accessed March 12.

APPENDIX A—TETRA TECH SITE VISIT WASTEWATER SYSTEM

PHOTOS


Page A-1

Photo A1. Lift Station B-1

Photo A2. Treatment System A2


Page A-2

Photo A3. Lift Station B-2

Photo A4. Lift Station B-2 Interior


Page A-3

Photo A5. Treatment System B Blower

Photo A6. Treatment System B Dosing Tanks


Page A-4

Photo A7. Treatment System B Access Hatch

Photo A8. Treatment System B Settling Tank


Page A-5

Photo A9. Treatment System B

Photo A10. Treatment System B


Page A-6

Photo A11. Treatment System B Blower Interior

Photo A12. Sample MicroFAST Treatment Media


Page A-7

Photo A13. Treatment System A2 Adjacent to Drinking Water Well

Photo A14. Monitoring Well A2 Adjacent to Leach Field A2


Page A-8

Photo A15. Treatment System A1

Photo A16. Drinking Water System Piping

APPENDIX B—2004 EPA WASTEWATER SYSTEM INSTALLATION

PHOTOS


Page B-1

Photo B1. Treatment System Tanks

Photo B2. Downstream End of Dosing Tanks


Page B-2

Photo B3. Dosing Tanks to Top of Leach Field Connection

Photo B4. Dosing Tank Outlets


Page B-3

Photo B5. Distribution Box from Treatment Tanks to Dosing Tanks

Photo B6. Distribution Box from Treatment Tanks to Dosing Tanks


Page B-4

Photo B7. Interior of Distribution Box

Photo B8. Dosing Tank Inlet


Page B-5

Photo B9. Treatment Tanks during Construction



Page B-6


Photo B12. Backfilling Leach Field Distribution Lines


Page B-7

Photo B13. Backfilling Leach Field Distribution Lines

Photo B14. Lining above Leach Field Distribution Lines


Page B-8

Photo B15. Backfilling over Leach Field Distribution Lines

Photo B16. Leach Field Distribution Line Construction


Page B-9

Photo B17. Leach Field Distribution Line Construction

Photo B18. Backfilling over Leach Field Distribution Lines


Page B-10

Photo B19. Leach Field Distribution Lines

Photo B20. Leach Field Distribution Lines


Page B-11

Photo B21. Leach Field Distribution Lines and Cleanouts

Photo B22. Leach Field Distribution Lines and Cleanouts


Page B-12

Photo B23. Aerial View of Leach Field Construction

APPENDIX C—WASTEWATER SYSTEM AND DRINKINGWATER SYSTEM MAPS

PINEVIEW ESTATES

GARDNERVILLE, NV

DRAWING SCALE NOT VALID UNLESS PLOTTED ANSI D SIZE

0 100

SCALE IN FEET

1"=100'

400200

N

LEGEND:

DRINKING WATER LINE

ROAD OR PAVED AREA

RESIDENCE

WATER STORAGE TANK

FENCE LINE OR LOT BOUNDARY

PROPERTY BOUNDARY

W

GROUNDWATER MONITORING WELL

LOCATIONS OF DRINKING WATER LINES ESTIMATED FROM 2002 LUMOS AND ASSOC. SITE PLANS

COORDINATE SYSTEM:

NAD83 STATE PLANE

NEVADA WEST

DRINKING WATER WELL

DRINKING WATER SYSTEM

GRAVEL

EARTH BERM

WASTEWATER SYSTEM AND DRINKING

WATER SYSTEM ASSESSMENT, FINDINGS,

AND ALTERNATIVES

PINEVIEW ESTATES

GARDNERVILLE, NV


0 100

SCALE IN FEET

1"=100'

400200

N

LEGEND:

WASTEWATER LINE (GRAVITY)

ROAD OR PAVED AREA

RESIDENCE

TREATMENT UNIT OR LIFT STATION

WATER STORAGE TANK


PROPERTY BOUNDARY

W

GROUNDWATER MONITORING WELL

LOCATIONS OF WASTEWATER LINES WERE ESTIMATED FROM 2008 EXD ENGINEERING SITE PLAN

COORDINATE SYSTEM:

NAD83 STATE PLANE

NEVADA WEST

DRINKING WATER WELL

WASTEWATER LINE (PRESSURIZED)

WASTEWATER SYSTEM SITE PLAN

GRAVEL

EARTH BERM



AND ALTERNATIVES

PINEVIEW ESTATES

GARDNERVILLE, NV


0100

SCALE IN FEET

1"=100'

400200

N

LEGEND:

DISPOSAL ALT 2: EFFLUENT DISCHARGE LINE

ROAD OR PAVED AREA

RESIDENCE


PROPERTY BOUNDARY

COORDINATE SYSTEM:

NAD83 STATE PLANE

NEVADA WEST

PROPOSED ALTERNATIVES

GRAVEL

EARTH BERM



AND ALTERNATIVES

APPENDIX D—WASTEWATER ALTERNATIVE ROM COSTS

TitleProject #

Project Name

Location

Name Date

Quantities A. Kanold 3/19/2012

Costs S. Tamburini 3/19/2012

Checked By C. Chavez 3/20/2012

Approved By C. Chavez 3/20/2012

Assumptions

Item No Quant. Unit Unit Cost Total

1 25 CY $550 $13,750

2 1 EA $75,000 $75,000

3 400 SF $120 $48,000

4 560 CY $10 $5,600

5 75 CY $550 $41,250

6 1 LS $295,000 $295,000

7 Piping 1 LS $12,000 $12,000

8 1 LS $98,120 $98,120

9 1 LS $34,342 $34,342

$623,062

10 $93,459

11 $49,845


13 Permitting (5%) $31,15314 $93,459

$941,000(1) Includes secondary treatment, sludge holding, disinfection

Civil Site

Construction Subtotal

Total Construction Cost

Profit (15%)

Design (8%)

Estimating Contingency (15%)

Mechanical Screen, Washer/Compactor

Pre-Engineered Headworks Building

Excavation, Backfill, Compaction for Packaged Plant

Packaged Plant Slab

Packaged Plant Equipment Package(1)

Electrical, Instrumentation and Controls

Unit costs assume typical installation of the proposed systemfeatures. Detailed design analysis may result in

significant reduction ofsystemfeatures to meet project objectives, thereby reducing estimated construction

costs.

Comments:

Quantities are based on the conceptual site plans.

Description

Headworks Slab

Treatment Alternative 1 ROM Construction Cost100-SMX-T28882

Wastewater Systemand Drinking Water SystemAssessment, Findings, and Alternatives

Pineview Estates Development, Gardnerville, Nevada

Description

This sheet provides a "ROM" construction cost estimate based on the conceptual wastewater treatment and

disposal alternatives for Pineview Estates wastewater system.

TETRA TECH, Inc.

Title

Project #

Project Name

Location

Name Date





Assumptions


1 25 CY $550 $13,750

2 1 EA $75,000 $75,000

3 400 SF $120 $48,000

4 560 CY $10 $5,600

5 250 CY $550 $137,500

6 1 LS $225,000 $225,000

7 Piping 1 LS $12,000 $12,000

8 1 LS $103,370 $103,370

9 1 LS $36,180 $36,180

$656,400

10 $98,460

11 $52,512


13 Permitting (5%) $32,820

14 $98,460

$991,000

Treatment Alternative 2 ROM Construction Cost

100-SMX-T28882

Wastewater System and Drinking Water System Assessment, Findings, and Alternatives


Description

This sheet provides a "ROM" construction cost estimate based on the conceptual wastewater

treatment and disposal alternatives for Pineview Estates wastewater system.

Unit costs assume typical installation of the proposed system features. Detailed design analysis may

result in significant reduction of system features to meet project objectives, thereby reducing

estimated construction costs.

Comments:


Description

Headworks Slab

Mechanical Screen, Washer/Compactor

Pre-Engineered Headworks Building

Excavation, Backfill, Compaction for Packaged Plant

Secondary Treatment Concrete

AeroMod Equipment Package

Electrical, Instrumentation and Controls

Civil Site


Profit (15%)



Design (8%)

TETRA TECH, Inc.

Title

Project #

Project Name

Location

Name Date





Assumptions


1 2,530 LF $25 $63,250

2 1 EA $5,000 $5,000

3 2 EA $14,000 $28,000

4 1,500 CY $18 $27,000

5 3,600 LF $32 $115,200

6 200 LF $50 $10,000

$248,450

7 $37,268

8 $19,876


10 $37,268

$363,000


Profit (15%)



Reconnect Abandoned Leach Field A Lines

Additional Monitoring Wells

Connection from New Treatment Plant

Design (8%)

Fill Material to Reduce Leach Field B Slope

Re-Installation of Leach Field B Lines

Unit costs assume typical installation of the proposed system features. Detailed design analysis may

result in significant reduction of system features to meet project objectives, thereby reducing

estimated construction costs.

Comments:


Description

Additional Leach Field Lines - 6" PVC

Disposal Alternative 1 ROM Construction Cost

100-SMX-T28882



Description



TETRA TECH, Inc.

Title

Project #

Project Name

Location

Name Date





Assumptions


1 3,100 LF $60 $186,000

2 1 EA $15,000 $15,000

3 8 EA $500 $4,000

4 1 EA $5,000 $5,000

$210,000

5 $31,500

6 $16,800


8 Permitting (5%) $10,500

9 $31,500

$317,000



Leach Field Closure

Monitoring Well Closure

Effluent Pipe Outlet Structure


Profit (15%)

Design (8%)

Unit costs assume typical installation of the proposed system features. Detailed design analysis

may result in significant reduction of system features to meet project objectives, thereby

reducing estimated construction costs.

Comments:


Description

Effluent Discharge Pipe

Disposal Alternative 2 ROM Construction Cost

100-SMX-T28882



Description



TETRA TECH, Inc.

APPENDIX E—REPORT PRESENTATION MEETING MINUTES AND

COMMENT RESPONSE SPREADSHEET

April 11, 2012 Draft Planning Document Review Meeting Minutes

Pineview Estates Wastewater Treatment Systemand Drinking Water System Assessment, Findings and Alternatives

10 April 2012Presentation Meeting Minutes

Location: Teleconference and Bureau of Indian Affairs Western Regional Office(311 East Washington Street, Carson City, NV)

1. Meeting Began 14002. Introductions – All meeting attendees introduced themselves and their interest in this project.

The meeting attendance roster is attached.3. Project Introduction

a. John Krause of the Bureau of Indian Affairs (BIA) Western Region Office provided a briefproject background and explained the scope of work.

4. Draft Planning Document Presentationa. Tetra Tech explained the scope of work for this project and provided an overview of the

presentation. Tetra Tech explained that this assessment and feasibility evaluation didnot include final design plans and specifications, but provides conceptual level designand cost estimates..

b. Tetra Tech briefly reviewed the documents reviewed for this project including:i. Existing site plans for the drinking water and wastewater systems from previous

engineering firms. These drawings were given to Tetra Tech in hard copy formatbut converted to electronic format by Tetra Tech.

ii. Previous engineering design calculations for the wastewater disposal field thatwere a supplement to the United States Environmental Protection Agency (USEPA) Underground Injection Control (UIC) permit.

iii. Existing treatment system specificationsiv. Water quality results from the existing wastewater treatment plant (WWTP)

influent, effluent, and at each of the monitoring wells.v. Treatment system maintenance logsvi. US EPA UIC Permit application and approved permit

c. Tetra Tech explained the components and function of the Pine View Estates drinkingwater system from the source well to distribution and storage.

i. A question was asked regarding the chlorination unit that was taken out ofservice. It was clarified that the chlorinator was taken out of service since it hadnot worked for several years and was depositing rust on adjacent piping.

d. Tetra Tech explained the assessment process and results of the drinking water systemevaluation.

i. Tetra Tech recommended replacing the chlorination unit, installing backuppower supply and backup source well.

ii. A question was asked if the drinking water system would meet staterequirements in its current state. Are there any upgrades that would berequired if the allotted land was to become fee land? Tetra Tech agreed toinvestigate state requirements for the drinking water system.


e. Tetra Tech explained the components and function of the wastewater collection,treatment, and disposal system.

i. Tetra Tech explained the wastewater demand, as recorded by flow meters attreatment systems A1 and B.

ii. Tetra Tech explained that the system as a whole has the capacity to treat allwastewater, but flows are being mis-directed and system A1 is beingoverloaded.

f. Tetra Tech discussed the monitoring well sampling resultsi. Fecal coliform results are consistently greater than the Maximum Contaminant

Limit (MCL) of zero coliform units.ii. A comment was made to remove “zero” values from the report graphics for

days when samples were not taken. Tetra Tech agreed to remove these valuesfrom graphics in the report.

iii. Results show that the existing treatment systems are not removing bacteria ornitrogen from wastewater to regulatory levels.

iv. Total Nitrogen results for treatment systems at leach field A are consistentlyabove MCL of 10 mg/L.

v. A comment was made that the treatment systems are actually increasingcontaminant levels observed in the wastewater effluent.

g. Tetra Tech explained the assessment process and results of the wastewater collectionand treatment system evaluation

i. Odors are affecting adjacent residencesii. Septic tanks have potential to impact homeowners due to backupsiii. Treatment systems not removing solids, organics, or nitrogen as designed.iv. Tetra Tech’s evaluation concluded that treatment deficiencies can be attributed

to the lack of biomass buildup, inadequate oxygen mixing, and inadequateanaerobic tank volume.

h. Tetra Tech explained the assessment process and results of the wastewater disposalsystem evaluation

i. Wastewater demands into leach fields A1 and A2 are exceeding leach fieldcapacities

ii. Leach field B slope is too steepiii. Leach field A1 is in disrepair and most likely leaking

i. Tetra Tech explained the alternatives excluded from additional technical and economicanalysis

i. Retrofit existing WWTP would be ideal, but this alternative was determined tobe too costly and future performance /compliance is suspect

ii. Individual leach fields at households – not enough area available at each lot forthese disposal systems

iii. Land application of tertiary treated wastewater was determined to be infeasibledue to local climate and freezing concerns

iv. Rapid Infiltration Basins (RIB) are still limited by soil infiltration rates and highcapital costs to construct

j. Tetra Tech explained their selection criteria for the preferred alternatives


k. Tetra Tech outlined the preferred wastewater treatment alternative (packagedtreatment plant) and answered questions regarding the second proposed/evaluatedtreatment alternative.

i. It was requested that a picture of the proposed treatment system be added tothe report. Tetra Tech agreed to add a photo to the final report.

ii. A question was asked about odor from wet sludge at the treatment system.Tetra Tech responded that the wet sludge odors would be limited by the closedsludge storage tank and aeration within the system. Tetra Tech also explainedthat the odor potential would be the same as the current system and across allsystems evaluated.

l. Tetra Tech outlined the preferred disposal alternative of a surface discharge and thebenefits of a surface discharge.

i. Questions were asked regarding downstream limitations from private landowners and water quality in the Carson River. Tetra Tech agreed to investigateTMDLs in the Carson River and include discussion in the final report.

m. Tetra Tech provided a summary of the preferred alternative – packaged treatment plantand surface discharge.

5. Meeting Adjourned 1600

REVIEW COMMENTSBIA StakeholdersDate: 10 April 2012Draft Planning Document ReviewProject: Pineview Estates Wastewater System and Drinking Water System Assessment, Findings, and AlternativesPrepared by: Adam Kanold, PE

Reference: Reviewer Cmnt # Comment Tetra Tech Response Proposed Action Action Taken

General SL 1

Did Tetra Tech not include a budget for the drinking water system

recommendations because they are fairly low-priority by EPA standards and do

not need to be complied with in order to meet SDWA standards?

Yes, that is correct. None of the proposed

alternatives include upgrades to the existing

drinking water system since the system is currently

in compliance with federal requirements.

Section 4.0 of report updated to include sentence

clarifying Tetra Tech's response.Sentence added to Section 4.0.

General SL 2

The second disposal budget does not seem to include cost estimates for

surface water discharge permit or indicate whether an NPDES or NDEP permit

would be needed and their difference in cost.

Tetra Tech's cost estimates assumed that

permitting costs would be covered by the "design"

and "contingency" line items. Tetra Tech will break

out the permitting costs in the final planning

document cost estimates.

Break out permitting costs in the final planning

document.

Cost estimates within the report and in Appendix D

now include a line item for permitting.

Page 23 Table

12,KK 3

BOD5 concentration of 130 a day for loading is too low. New homes with new

fixtures are giving us BOD5 loadings of 480 up from the old standard of 240.

Both treatment alternatives assume that septic

tanks will not be removed from the wastewater

collection system and therefore, design loading

rates for BOD5 will remain lower than typical

domestic wastewater, or approximately 130 mg/L.

Comment addressed. Sections 4.2 and 4.3 of the

report updated to clarify that treatment alternatives

assume septic tanks remain in place.

Report updated as proposed.

General KK 4 In regards to hauling of wet sludge (3-5%); is expensive.

The hauling costs are high due to long hauling

distances to sludge disposal facilities. Summit

Plumbing indicated that a long term hauling contract

may lower the hauling cost but for the purposes of

this report, the hauling costs shall remain as a

conservative estimate, assuming only a short term

contract.

Comment addressed. No proposed change to

report.No proposed change to report.

General KK 5 Discharge of the effluent to the surface could be very difficult to permit. See comment #21. See comment #21. See comment #21.

General KK 6 The closure of the septic tanks is important to assure good plant operation

Both treatment system designs proposed in the

planning document assume the septic tanks will

remain in place and are designed with

headworks/grit removal that will effectively remove

any additional solids entering the system. Leaving

the septic tanks in place will not adversely affect the

proposed treatment systems. Tetra Tech

recommends leaving them in place and the

development of a septic tank maintenance plan.

Sections 3.4.2 and 5.0 of the report updated to

clarify technical opinion of septic tank impacts to

wastewater system.

Report updated as proposed.

p.24 Line 7 SC 7 should be “manufacturers.” Agreed. Update text. Text updated.

2d paragraph

line 4SC 8

“as far as possible toward” Did they mean “as far as possible from”? or “as

close as possible”?

Document should say "as far as possible away from

the residential area."Update text. Text updated per comment response.

4th paragraph

line 5SC 9 “absorption.” Agreed. Update text. Text updated.

p. 25 line 2 SC 10 “out of the water” Agreed. Update text. Text updated.

4th paragraph

last lineSC 11 “will then be taken” Agreed. Update text. Text updated.

p.26 1st

paragraph line

5

SC 12 Remove T from Tall. Agreed. Update text. Text updated.

General DA 13

Will the capacities of treatment alternative #1 and disposal alternative #2 meet

or exceed full build out of 231 units at a flow rate of 80 gallons person at 2.59

people per home?

Yes, both treatment alternative 1 and disposal

alternative 2 will meet full build out requirements.

However, full build out of the subdivision is 211

homes, not 231 homes.

Add sentence to Section 4.0 to clarify that all

alternatives meet full build out capacity needs.Text updated.

General DA 14The tentative costs of $1,175,000 capital cost and $105,400 O&M costs are

projected for full build out of 231 units?

Yes. Tetra Tech's evaluation and cost estimate

assumes full build out of the subdivision at 211

homes.

Add sentence to Section 4.0 to clarify intention. Text updated.

Page 1, para

2JK 15 remove sentence "provides administrative oversight at Pineview Estates"

Agreed. See comment #26 for alternate text used

in report.Update text per comment #26. Text updated per comment #26.

General JK 16 change all references to "tribal" lands to "allotted" lands. Agreed. Update text. Text updated.

Figures 4 and

5JK 18

remove points from plot that show "zero" value for dates when MW not

sampled.Agreed.

Figures 4 and 5 updated to remove "zero" values

on dates when samples were not taken.Figures 4 and 5 replaced.


Section 4.2.3 JK 19 first sentence, change "with" to "will" Agreed. Update text. Text updated.

Section 4.2 JK 20 Add picture of WWTP in treatment alternative 1 Agreed. Picture added to Section 4.2. Report updated.

General All 21

Please investigate downstream water rights, TMDL, or protected waters issues

that could prevent the preferred disposal alternative from being implemented

and include this discussion in the report.

The Carson River is impaired for several

parameters and TMDLs have been established for

phosphorus, turbidity, and total suspended solids.

Tetra Tech reviewed the TMDLs that have

established for the Carson River as well as Nevada

water quality standards. Based on this review, the

proposed treatment system is expected to meet

applicable water quality standards and be permitted

as proposed by the Nevada Division of

Environmental Protection. As an example, the

phosphorus TMDL includes reference to the

nitrogen water quality standard of 10 mg/l, but this

TMDL does mention that water quality standards

could be changed in the future, which could impact

the proposed wastewater treatment system at Pine

View Estates. Tetra Tech has included a 20%

contingency in the project cost estimate should

water quality standards be changed or if the Nevada

regulatory agency requires additional treatment

technologies.

Section 4.4 will be updated to reflect this

information.Text updated

General All 22

Do state regulations require the drinking water system to have the redundancy?

(items such as a chlorination unit, backup source well, backup power, etc.?).

Would the drinking water system be in compliance if the subdivision was to

become fee land instead of allotted land?

State regulations (Nevada Administrative Code

(NAC)), enforced by the Nevada Department of

Environmental Protection (NDEP), would require the

Public Water System at Pineview Estates to

undergo a permit application process to include

submittal and review of drinking water system as-

built drawings, system hydraulic model, well pump

test results, and NDEP would perform a site visit to

the Pineview Estates drinking water system. Tetra

Tech is unaware of an existing hydraulic model or

as-built drawings for the existing drinking water

system. The Engineering Department at NDEP

explained that given the size and rural location of

Pineview Estates, the drinking water system would

be required to have a second source well that

meets fire flow and average daily demand flows and

a backup power supply in order to comply with state

regulations.

Explanation of regulatory requirements will be

added to Section 3.1 of report.Text updated.

General All 23 Is chlorination required by state and federal regulations?

The current water system at Pineview Estates does

meet the primary drinking water standards under

federal regulations/jurisdiction so a chlorination

device is not currently required; however, Tetra

Tech does recommend that the chlorination unit be

replaced so that disinfection can be accomplished in

the future should the need arise. Chlorination is not

required by state regulations if the source well

meets all primary drinking water standards, if water

is obtained from a well that is located and

constructed in accordance with state regulations,

and if the distribution system is constructed in a

manner that complies with state regulations. It

should be noted that disinfection does trigger

additional sampling, MCL, and compliance

requirements.

Explanation of regulatory requirements will be

added to Section 3.1 of report.Text updated.

General All 24

What are the estimated costs for permitting each alternative? What are the

costs for engineering design? Cost for construction oversight? Please include

in your report.

Estimated permitting costs are 5% of the subtotal.

Estimated construction oversight costs are 8% of

the sub total. These line items will be broken out in

the updated cost estimates for both treatment

alternatives and disposal alternative 2.

Update cost estimates. Updated cost estimates.


Section 4.5 All 25Improve discussion of discharge location point and applicable regulations. Is

NDOT ROW a concern to permitting this pipe?

Discharge point will avoid private property and the

NDOT will require a right-of-way occupancy permit

prior to installation of the wastewater line. Permit

application will require design plans and

specifications, a traffic impact study, and a drainage

report. This discussion added disposal alternative 2

discussion in report.

Discussion added to Section 4.4 of report. Text updated.

p.1 AB 26

“The Bureau of Indian Affairs (BIA) provides administrative oversight at

Pineview Estates . . .” it should more correctly read, “The BIA currently holds in

trust for the Indian allottee the land on which Pineview Estates is located and

has . . .”

Agreed. Update text. Text updated.

p. 3 AB 27

“The existing system is located on tribal lands” should more appropriately read,

“The existing system is located on a public domain allotment held in trust on

behalf of an Indian Landowner . . .”

Agreed. Update text. Text updated.

p. 4 AB 28

states Pineview Estates is currently under “federal jurisdiction since it is located

on tribal lands,” - I’ll let you wordsmith it, however, in this case, the BIA holds

this land in trust for the allotted Indian Landowner. The land belongs to the

allottee, but is held in trust by the BIA. Allotted land is not Tribal land. It is

owned by an individual or individuals, not the Tribe.

Agreed. Sentence removed from text as it is not

required to convey purpose of this section.Update text. Text updated.

p. 6 AB 29“if the tribal land is transferred . . .” it should more correctly read, “if the allotted

land held in trust is transferred to fee . . .”Agreed. Update text. Text updated.

Section 5 LFB 30

Please improve discussion regarding septic tank recommendations. Does the

existing system require removing the tanks? What is the approximate cost of

removing all septic tanks?

See comment #6. See comment #6. See comment #6.

End of Comments

2012-April-16 Tetra Tech Final Planning Document for Pine View Estates

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Transcript of 2012-April-16 Tetra Tech Final Planning Document for Pine View Estates