Advanced Design and - University of Minnesota Wittwer 612-624-7460 [email protected] Workshops, ......

2009—2010

Advanced Design and Inspecti on - I

More informati on is available at our website: htt p://septi c.umn.edu

3Take HomeBrought to you by. . .

and the

OSTP Sta can answer ques ons about workshops, U of MN Publica ons, soils, designs, forms, small community issues and technical assistance.

2009-2010 Key Contact Informa on Contact the appropriate organiza on to get your ques ons answered faster!

Minnesota Pollution Control Agency SSTS Contact Information520 Lafayette Road North St. Paul MN 55155 – Email: [email protected] – 651-296-6300 or 800-657-3864

The MPCA can answer ques ons about your business license, professional cer ca on, state rule interpreta on, local ordinance assistance, and business complaints.

Staff person Phone and Email Area of expertise

Clarence Manke St. Paul

[email protected]

Metro Area: Ordinance & Technical Assistance, SSTS Business Complaints, Tank fee, Rule Interpretation

Pat Shelito Brainerd

[email protected]

Central MN and Temporary North East MN: Ordinance & Technical Assistance, SSTS Business Complaints, Rule Interpretation

Brian Green Rochester

[email protected]

South East MN: Ordinance & Technical Assistance, SSTS Business Complaints, Rule Interpretation

Nick Reishus Marshall

[email protected]

South West MN: Ordinance & Technical Assistance, SSTS Business Complaints, Rule Interpretation

Heidi Lindgren Detroit Lakes

[email protected]

North West MN: Ordinance & Technical Assistance, SSTS Business Complaints, Rule Interpretation

Ron Swenson Brainerd

[email protected]

Statewide: Enforcement Supervisor

Mary West St. Paul

[email protected]

Statewide: Program Administration; Technical, Soils and General Ordinance Assistance (backup to regional staff ); Annual Report

Barb McCarthy Duluth

[email protected]

Statewide: SSTS Tank and Product Registration, Soils and Technical Assistance (backup to regional staff )

Mark Wespetal St. Paul

[email protected]

Statewide: Program Administration, Technical Assistance (backup to regional staff )

Gretchen Sabel St. Paul

[email protected]

Statewide: Program Administration, Legislative Issues, General Ordinance Assistance (backup to regional staff ), South West MN Ordinance and Technical Assistance

Bill Priebe St. Paul

[email protected]

Statewide: SSTS Program Policy and Planning Supervisor

Jane Seaver St. Paul

651-757-2201 ext. 2-1; [email protected]: 651-297-8676

Statewide: Individual Certification & Business Licensing

Staff Person Telephone Email Area of expertiseNick Haig 612-625-9797 [email protected] Workshop questions, UMN publications

Jessica Wittwer 612-624-7460 [email protected] Workshops, soils, landscaping

Sara Heger Christopherson

612-625-7243 [email protected] Technical information, design forms

Dave Gustafson 612-625-1774 [email protected] Technical information

Dan Wheeler 612-625-8791 [email protected] Soils, mapping, soil survey

Laurie Brown 218-726-6475 [email protected] Northern MN – Small community, management, or homeowner issues, soils

Doug Malchow 507-280-5575 [email protected] Southern MN – Small community, management, or homeowner issues

University of Minnesota Onsite Sewage Treatment ProgramWater Resources Center • 1985 Buford Avenue, 173 McNeal Hall • St. Paul, MN 55108

(800) 322-8642 • FAX: (612) 624-6434 • Email: sep [email protected] • Web site: h p://sep c.umn.edu

Advanced Design and Inspecti on Take Home 3

#2:Design a gravity collecti on system for 3 Class I (3 bedroom) and 3 Class I (4 bedroom) homes. Each home connects to the gravity collecti on system directly (no septi c tank or effl uent screen). The home lots are in line along Eagle Road and have a front lot dimension of 170 feet. Assume there is 170 feet between individual home connecti ons and the treatment site is 600 feet from the last home connecti on. Use minimum slope.

Questi ons:

A. What type and size pipe should be used for this collecti on system?

B. Determine the design fl ow of the collecti on system.

C. Will a 6 inch diameter gravity collecti on pipe have capacity to carry 50% of the daily fl ow in 1 hour?

D. If this project were in St. Louis County, what is the minimum depth the gravity collecti on pipe can be without insulati on?

E. Assume the gravity pipe is placed at minimum depth at the fi rst home connecti on. What is the depth of the gravity pipe at the treatment site using the minimum allowable slope?

Take Home Assignments:Instructi ons: 1. You will need to use resources from the Advanced Design and Inspecti on course and additi onal informa-

ti on available at the Advanced Design and Inspecti on web page: htt p://septi c.umn.edu/professionals/adresources/index.htm

2. Use the space provided for your answers. Show all of your work on additi onal paper, if necessary.

3. Site descripti ons for Heggy’s Golf Course, Wheelerville Heights and Haig’s Dwelling are in Course Packet #2, pp 3-12.

4. Good Luck!

#1: Use the Heggy’s Golf Course site descripti on and answer the following questi ons:

A. What is the design fl ow?

B. What is the esti mated BOD loading?

C. What size grease trap would be required?

Advanced Design and Inspecti on Take Home4

#3: Collecti on System Design

Use the Wheelerville Heights descripti on to answer the General, Gravity Sewer, STEP System, and Pres-sure System with Grinder Pumps questi ons:

General questi ons:A. Calculate the fl ows for the collecti on system design value and the permit value?

B. For a gravity collecti on system what would the peak fl ow for the lift stati on design?

C. What is the required septi c tank capacity?

D. If the minimum bury depth of the pipe is 7 feet: what would its beginning pipe elevati on be on at point A?

E. What would be elevati on be of the piping at the corner using 4” pipe?

F. What would the elevati on be at the discharge point using 4” pipe? a. Using 2” pipe? b. Using 8” pipe?

Gravity SewerA. Would you recommend a lift stati on with 4” piping? Why/why not?

B. How many manholes would be required with this design?

C. For a gravity system would it require any thrust blocks?


STEP System A. If a STEP system is used on each property, what is the sti lling tank capacity for the system?

B. What is the esti mated number of pumps that will be operati ng at any one ti me?

C. Assuming a fl ow of 6.25 gallons per minute; what would the design fl ow for the fricti on loss be in the system?

D. What would the esti mated fricti on loss be in the system?

E. What would the required pump sizing be for these homes?

F. Where would thrust blocks be required?

G. Where would clean outs be required?

Pressure System with Grinder PumpsA. What is the esti mated number of pumps that will be operati ng at any one ti me?

B. Assuming a fl ow of 11 gallons per minute, what would the design fl ow for the fricti on loss be in the system?

C. What would the esti mated fricti on loss be in the system?

D. What would the required pump sizing be for these homes?

E. Where would thrust blocks be required?

F. Where would clean outs be required?


# 4: Timer Design

During troubleshooti ng a mound system it is determined that is being hydraulically overloaded. During a typical week, 3,000 gallons of wastewater are being delivered to the mound with 50% of that occurring Fri-day – Sunday night. Given the following characteristi cs, set-up the ti me-dosing for the system • 4 bedroom home with heavy weekend use (common guest, parti es, etc) • 20 gallons per inch in dosing tank • Liquid depth = 60 inches • 2” pipe up to soil treatment = 100’ • 30 gpm pump


DETERMINE AREA AND/OR GALLONS PER INCH

1. A. Rectangle area = Length (L) X Width (W)

ft X ft = ft2

B. Circle area = 3.14r2 (3.14 X radius X radius)

3.14 X 2 ft = ft2

C. Tank model and manufacturer (optional):

C. Get area from manufacturer ft2

D. Get gallons per inch from manufacturer Gallons per inch

2. Calculate Gallons Per Inch :

(Area X 7.48 gallons/ft3)/(12 in/ft) =

ft2 X = Gallons per inch

3. Enter the Pump Tank Capacity (minimum provided in the table below): Gallons

4. Calculate Total Tank Volume

A. Depth from bottom of inlet pipe to tank bottom : in

B. Total Tank Volume = Depth from bottom of inlet pipe (Line 4.A) X Gallons/Inch (Line 2)

in X Gallons Per Inch = Gallons

5. Calculate Volume to Cover Pump (The inlet of the pump must be at least 4-inches from the bottom of

7.48 gal/ft3 ÷ 12 in/ft

TANK CAPACITY

There are 7.48 gallons per cubic foot. Therefore, multiply the area from 1.A, 1.B, or 1.C by 7.48 to determine the gallons per foot the tank holds. Then divide that number by 12 to calculate the gallons per inch.

OSTP Pump Tank Sizing, Dosing and Float and Timer Setting Design Worksheet

Width

Length

Radius

5.

(Pump and block height + 2 inches) X Gallons Per Inch (1D or 2)

( in + 2 inches) X Gallons Per Inch = Gallons

6. Gallons

- Line 17 of the Pressure Distribution or Line 11 of Non-level

7. Calculate Maximum Pumpout Volume (25% of Design Flow)

Design Flow: GPD X = Gallons

8. Gallons

9. Calculate Doses Per Day = Design Flow ÷ Dosing Volume

gpd ÷ gal = Doses

10. Calculate Drainback:

A. Diameter of Supply Pipe = inches

B. Length of Supply Pipe = feet

C. Volume of Liquid Per Lineal Foot of Pipe = Gallons/ft

D. Drainback = Length of Supply Pipe X Volume of Liquid Per Lineal Foot of Pipe

ft X gal/ft = Gallons

11. Total Dosing Volume = Dosing Volume (Line 8) plus Drainback (Line 10.D)

gal + gal = Gallons

12. Minimum Alarm Volume = Depth of alarm (2 or 3 inches) X gallons per inch of tank (Line 1 or 2)

in X gal/in = Gallons

Calculate Volume to Cover Pump (The inlet of the pump must be at least 4 inches from the bottom of the pump tank & 2 inches of water covering the pump is recommended)

Minimum Pumpout Volume - 5 X Volume of Distribution Piping:

0.25

DOSING VOLUME

Select a pumpout volume that meets both items above (Line 6 & 7):

Width

Length

Radius



TIMER or DEMAND FLOAT SETTINGS

Select Timer or Demand Dosing: 0

A. Timer Settings

13. Required Flow Rate :

A. From Design (Line 11 of Pressure Distribution or Line 10 of Non-Level*): GPM

B. Or calculated: GPM = Change in Depth (in) x Gallons Per Inch (Line 1 or 2) / Time Interval in Minutes

in X gal/in ÷ min = GPM

14. Choose a Flow Rate from Line 13.A or 13.B above. GPM

15. Calculate TIMER ON setting:

Total Dosing Volume (Line 11)/GPM(Line 14)

gal ÷ gpm = Minutes ON

16. Calculate TIMER OFF setting:

Minutes Per Day (1440)/Doses Per Day (Line 9) - Minutes On (Line 15)

÷ doses/day - min = Minutes OFF

17. Pump Off Float - Measuring from bottom of tank:

Distance to set Pump Off Float=Gallons to Cover Pump (Line 5) / Gallons Per Inch (Line 1 or 2):

gal ÷ gal/in = Inches

18. Alarm Float - Measuring from bottom of tank:

Distance to set Alarm Float = Tank Depth(4A) - Alarm Depth (Line 13)

in - in = inB. DEMAND DOSE FLOAT SETTINGS

18. Calculate Float Separation Distance using Dosing Volume .

Total Dosing Volume (Line 12)/Gallons Per Inch (Line 2)


*Note: This value must be adjusted after field

measurement & calculation.

1440 min

Timer Demand Dose

19. Measuring from bottom of tank:

A. Distance to set Pump Off Float = Pump Height + Block Height (Line 5) + Alarm Depth (Line 13)

in + in = Inches

B.

in + in = Inches

C. Distance to set Alarm Float = Distance to set Pump-On Float (19.B) + Alarm Depth (2-3 inches)

in + in = Inches

in Alarm Depth in

Pump On in

Pump Off in Pump Off in

I hereby certify that I have completed this work in accordance with all applicable ordinances, rules and laws.

(License #)

FLOAT SETTINGS

(Date)

TIMED DOSING

Distance to set Pump On Float=Distance to Set Pump-Off Float (Line 19.A) + Float Separation Distance (Line 18)

(Signature)(Designer)

Alarm Depth

DEMAND DOSING


#5: Registered Treatment Product Design ECOPOD Registered with and without UV Disinfecti on

Using Haig’s Dwelling Informati on, design a treatment system using an ECOPOD unit.

Use the rules and the MPCA website on Product Registrati on located at:htt p://www.pca.state.mn.us/programs/ists/productregistrati on.html to determine the following:

Treatment level required

Trash tank sizing

Ecopod Model

UV disinfecti on needed?

Housing for UV device

Size of pump tank for soil dispersal

Soil dispersal (type and depth)

Applicable soil loading rate tables to use

Soil loading rate

Soil dispersal system design

Method of distributi on


Provide a preliminary concept plan incorporati ng the system components with a cross-secti on of the soil dispersal system:


#6: Constructed Wetlands

A. In the operati on of wetlands, nitrogen and phosphorous may be assimilated by plant uptake, yet they both cannot be counted upon as being removed from the wastewater. Explain.

B. Explain why normal non-pathogenic organisms known as coliforms are used to identi fy the presence of pathogens in wastewater.

C. Although most species of animals are probably harmless or even benefi cial to the functi on of a constructed wetland, there are a few nuisance species. Name and describe two species and their impact on the wetland.

D. In general does the climate have any infl uence on the functi oning of a wetland? Explain.

E. In spite of the wetland’s inherent appeal, there may be ti mes when the designer may have the un happy experience of having to convince the public that they are not a viable opti on. Discuss.

F. At the present ti me wetland design is based upon current and reliable informati on. True or False? Discuss your answer.

G. A constructed wetland is 2000 ft 2 in area. Assume the surface edges of the constructed wetland are nearly verti cal. The media depth is 24 inches with the effl uent level maintained at 6 inches below the surface. The overall porosity (or void %) of the media surrounding the open surface area is 40%.

How much fl ow (total volume) would have to enter the wetland to increase the water surface by 0.5 inches? (Assume no outf low during this period.)


#7: Aerobic Treatment Units

A. Name and explain two problems that severely complicate the proper functi oning of an aerobic treatment unit.

B. The nati onal Sanitati on Foundati on (NSF) Standard 40 has some signifi cant omissions when used to properly defi ne the water quality of ATU effl uents. Explain.

C. Although there are two diff erent operati onal schemes used in small aerobic treatment units, there is one fundamental principle that remains the same for each scheme. Explain the fundamental process.

D. Explain a good way to judge the quality of acti vated sludge in an aerobic treatment unit.

E. Why is it likely that data from controlled laboratory testi ng of aerobic treatment units should be viewed with cauti on?

F. Unless modifi cati ons are made to the aerobic treatment unit, no signifi cant nitrogen removal can be expected. Explain why.

G. In the ATU an insignifi cant amount of phosphorous may be removed by sedimentati on. If more removal is desired, what would have to be done?

H. How many pounds of BOD removal due you need to bring 1300 GPD of sewage with a BOD5 of 800 mg/l down to Treatment Level C?


#8: Media Filters

1. Determine the recirculati on rati o for a texti le fi lter given • Flow = 500 gpd • The dose fl ow rate to the fi lter = 30 gpm • The dose frequency is every 10 minutes • The dose run ti me is 30 seconds

2. Design a recirculati ng sand fi lter for Wheelerville Heights (forms are att ached).

Determine: • Suitable gradati on for the fi lter media • Volume of pea gravel, drainfi eld rock, and fi lter media • Dimensions of the fi lter • Size of liner and any other material associated with the liner • Size of: o septi c tank o recirculati on tank o pump tank • Layout of the manifold and pressure distributi on system with pipe sizes and lengths along with perforati ons • Number and size of pumps • Number of doses provided at design fl ow


1. Flow from Dwellings Flow from Dwellings gpd

2. Flow from Other Establishments

Permitting Flow from Other Establishments

gpd

a) Total Length of CollectionPipe:

feet

b) Diameter of Pipe (Minimum of 2 in):

inches

c) Flow from I& I in Collection System:

gpd

gpd

OSTP Final Permitting FlowWorksheet

Design flow must include 200 gallons of infiltration and inflow

per inch of collection pipe diameter per mile per day with a minimum pipe diameter of two

inches. Flow values can be further increased if the system employs

treatment devices that will infiltrate precipitation.

4. Final Permitting Flow

From either existing and new development worksheet

From either Measured or Estimated-OE worksheet

Sum of 1, 2 and 3c.

3. Flow from Collection System


Permitting Flow (from Final Flow worksheet): GPD

A.

See Assessment and Waste Strength Table

B. If Yes, Estimated or Measured Values

i. BOD5 mg/l

ii. TSS mg/l

iii. FOG mg/l

Facility with potential elevated levels of BOD5, TSS or FOG?

If concentrations of BOD, TSS, and O&G are expected to be higher than 175 mg/1, 65 mg/1, or 25 mg/1 respectively, an estimated or measured

average concentration must be determined.

OSTP LISTS & MSTS Design Flow & System Summary

1. PERMITTING FLOW

3. GREASE TRAP

Grease trap required for facilities with high levels of O&G. A minimum of 24 hours (1 day) of hydraulic retention i i i d b b 4 d Th l b ffl d d 50 70% f li id d h

2. ORGANIC LOADING

Yes No

Estimated Measured

A. Design Flow - Grease Trap (kitchen waste only): GPD

Use 70% of permited flow to size the grease trap if using estimated design flows are being used.

B. Minimum capacity is equal to the Design Flow for Grease Traps (3A) multiplied by 1.

X day(s) = Gallons

A. Individual septic tanks at each dwelling (7080.1930 minimum)*:

Septic Tank capacity: Gallons

Number of Septic Tanks/Compartments:

(1/8 or 1/16 inch)

B. Stilling tank required?

If Yes, minimum capacity is equal to the Design Flow (Line 1) multiplied by 0.5 (can be greater than 0.5 )

X day(s) = Gallons

4. SEPTIC TANKS and STILLING TANK

time is required, but can be up 4 days or more.The outlet baffle must extended to 50 - 70% of liquid depth.

* When septic tanks are installed at each dwelling

an effluent screen and alarm must either be

located at each dwelling or a the common treatment area.

Effluent Screen Minimum Size Slots**

Yes No

Estimated Measured

Yes No



B. Gravity collection to common septic tanks:

Minimum capacity is the design flow (1) multiplied by 3 days.

X 3 days = Gallons

Number of Septic Tanks/ Compartments :

(1/8 or 1/16 inch)

C. Pressure collection to common septic tanks:

Minimum septic tank capacity is the design flow multiplied by 4 days.

X 4 days = Gallons

Number of Septic Tanks/Compartments :

(1/8 or 1/16 inch)

D. Septic tank liquid capacity prior to other treatment devices:


** 1/16 inch screen slots must be used when

downstream distribution components utulize 1/8 inch diameter orifices.


Gallons

Number of Septic Tanks/Compartments :

A. Depth to Limiting Layer : inches feet

B. Landscape Position :

C. Soil Texture Group Number :

D. Percent Land Slope : %

Effluent Screen & Alarm ?

5. SITE EVALUATION OVERVIEW:

Capacity set by manufacturer's requirements, accepted engineering principles, or as identified in the product registration recommended standards and criteria.

Yes No



A. B.

mpi

Grade

Consistence

*Rapidly permeable soils: see 7080.2260

Slowest measured percolation rate:

Texture

Texture Group

Select Soil Loading Rate:

Structure

7080 Table IX

DETAILED SOIL DESCRIPTIONS (SOIL PIT REQUIRED)

6. SOIL LOADING RATES: Select method A. or B. below

C. GPD/ft2

A. Type of Collection System

B.

C. Type of System:

D. Registered Product/pretreatment unit:

E. Distribution Method :

I hereby certify that I have completed this work in accordance with all applicable ordinances, rules & laws.

(License #) (Date)

Design Loading Rate:

Kind of Soil Treatment and Dispersal Area :

7. SYSTEM OVERVIEW

(Signature)

Select Soil Loading Rate:

(Designer)

Note: Pressure distribution must be used for soil treatment systems with flows greater than 2,500 gallons per day.

Gravity Pressure

Yes-Type:No

Type I Type II Type III Type IV Type V


A. GENERAL SPECIFICATIONS

1. Design flow - from Flow & Soil or LISTS Flow worksheet:

2. Type of filter (check ):

B. MINIMUM RECIRCULATION/DOSING TANK CAPACITY (if applicable)

A minimum of 24 hours (1 day) of hydraulic retention time is required, but can be greater.

Minimum capacity is equal to the Design Flow (1) multiplied by 1.

gpd X day(s) = Gallons

C. FILTER DIMENSIONS

1. Select hydraulic loading rate: ft2/gpd

Maximum hydraulic loading rate for single-pass is 1.0ft 2 /gpd and 0.2 ft 2 /gpd for recirculating.

2. Filter area based on hydraulic loading rate = flow rate (A1) x loading rate (C1):

gpd X ft2/gpd = ft2

OSTP Single-Pass & Recirculating Sand Filter

Worksheet

Single-Pass Recirculating

3. Verifty organic loading rate is accectable

a.

gpd X lbs BOD

b. Divide lbs of BOD by square feet of filter (C2).

lbs BOD ÷ ft2 = lbs BOD/ft2

c.

lbs BOD ÷ 0.005 = ft2

d.

4. Select width of filter: ft

5. Length of filter = filter area (C3d) divided by filter width (C3) =

ft2 ÷ ft = ft

Number of Zones:

1 zone minimum for single family dwelling, minimum of two zones for anything else.

Organic loading rate must be less then 0.005 lbs BOD/ft2. Divide lbs of BOD (Line 3a) by 0.005 lbs/ft 2

Required filter area is the larger of line C2 and 3c:

mg/l X 0.00000834 =

Take design flow (A1) multipled by estimated BOD5 multipled by conversion factor (0.00000834).

Single-Pass Recirculating



WorksheetD. DRAINAGE SYSTEM

1. Type(s) of Drainage Media:

2. (a) Total Depth of Drainage Media: ft

(b) Depth of Pea Gravel: in. ÷ 12 = ft

c) Depth of Drainfield Rock: in. ÷ 12 = ft

3.

ft2 X ft = ft3

Divide cubic feet by 27 ft3/yd3 to get cubic yards:

3 3

To protect the liner, 6 in. of 3/8- media must be installed under the liner and 2 in. of pea gravel on top of the liner. Drainfield rock must surround the collection pipe. The upper 2 in. must be pea gravel to limit migration of treatment media into drai

Pea Gravel Volume: Multiply filter area (C2) by drainage depth (2b):

Minimum depth is 1 foot with bottom sloped 1% to drainage pipe unless pump is part of filter drainage.

ft3 ÷ 27 = yd3

4.

ft2 X ft = ft3

Divide cubic feet by 27 ft3/yd3 to get cubic yards (for sand and gravel only):

ft3 ÷ 27 = yd3

5. Number of Drainage Pipes:

6. Number of Inspection Ports: One inspection port per zone is minimum.

Drainfield Rock Volume: Multiply filter area (C2) by drainage depth (2c):

One drainage pipe per zone or twenty feet is minimum, more are recommended to facilitate system recovery.



WorksheetE. TREATMENT MEDIA

1. Type (sand, gravel, etc):

2. Depth of Treatment Media: ft 2 feet is required

3. Treatment Media Volume: Multiply filter area(C2) by treatment depth (E2):

ft2 X ft = ft3

Divide cubic feet by 27 ft3/yd3 to get cubic yards

ft3 ÷ 27 = yd3

F. DISTRIBUTION MEDIA

1. Type of Distribution Media:

If other, please specify:

2. Depth of Distribution Media: ft

3.

ft2 X ft = ft3

Divide cubic feet by 27 ft3/yd3 to get cubic yards

ft3 ÷ 27 = yd3

G. COVER MATERIAL (if applicable)

Is the system covered with geotextile & soil (check box) ?

ft

Single-pass sand filters may be covered with soil while recirculating sand filter must have distribution media to the surface. If soil cover installed, maximum depth of 12 inches of loamy or sandy material with upper six inches of topsoil borrow is required along with appropriate vegetation.

Minimum depth is 0.67 feet (8 inches = 6 inches below the lateral and 2 inches above).

If using rock or gravel, media volume: Multiply filter area (C2) by distribution depth (F2):

Yes-Depth:No



WorksheetH. LINER

1.

ft + ft + ft +

ft = ft

2.

ft + ( ft x 2) + 2 = ft

3.

ft + ( ft x 2) + 2 = ft

4. Liner size/area is then determined by multiplying the width(H2) and length (H3):

ft2 X ft = ft2

Total system height is sum of depth of drainage(D2), treatment(E2), distribution(F2) & cover(G):

Length of liner equals the design length (C5) plus two times the total system height (H1) of the filter plus two additional feet for constructability:

Width of liner is equal to the design width (C4) plus the two times the total system height (H1) plus two additional feet for constructability:

Assumes vertical walls. If sloped additional liner will be

needed.


(License #) (Date)(Designer) (Signature)


1. Select Number of Perforated Laterals in system/zone :

(2 feet is minimum and 3 feet is maximum spacing)

2. Select Perforation Spacing : ft

3. Select Perforation Diameter Size inch 0

4. Length of Laterals = Media Bed Length - 2 Feet. Perforation can not be closer then 1 foot from edge.

- 2ft = ft

5.

Number of Perforation Spaces = ft ÷ ft = Spaces

6. Number of Perforations per Lateral is equal to 1.0 plus the Number of Perforation Spaces (Line 5).

Perforations Per Lateral = + 1 = Perfs. Per Lateral

7.

Perf. Per Lateral X Number of Perf. Laterals = Total Number of Perf.

8. Calculate the Square Feet per Perforation. Recommended value is 4-10 ft 2 per perforation.

D t l t At G d

OSTP Pressure Distribution Design Worksheet

Determine the Number of Perforation Spaces . Divide the Length of Laterals (Line 4) by the Perforation Spacing (Line 2) and round down to the nearest whole number.

Check Table I to verifty the number of perforations per lateral guarantees less than a 10% discharge variation. The value is double if the a center manifold is used.

Total Number of Perforations equals the Number of Perforations per Lateral (Line 6) multiplied by the Number of Perforated Laterals (Line 1).

Spaces

Does not apply to At-Grades

Bed Area = Bed Width (ft) X Bed Length (ft)

ft X ft = ft2

Square Foot per Perforation = Bed Area divided by the Total Number of Perforations (Line 7).

ft2 ÷ = ft2/perforations

9. Select Minimum Average Head : ft

10. Select Perforation Discharge (GPM) based on Table III: GPM per Perforation

11.

Perforations X GPM per Perforation = GPM

12. Select Type of Manifold Connection (End or Center):

Determine required Flow Rate by multiplying the Total Number of Perforations (Line 7) by the Perforation Discharge (Line 10).

perforations

End Center


OSTP Pressure Distribution Design Worksheet

14. Select Lateral Diameter based on Table I: in

15. Volume of Liquid Per Foot of Distribution Piping : Gallons/ft

16. Volume of Distribution Piping =

X ft X gal/ft = Gallons

17. Minimum Dose = Volume of Distribution Piping (Line 17) X 5

Gallonsgals X 5 =

= [Number of Perforated Laterals (Line 1) X Length of Laterals (Line 4) X (Volume of Liquid Per Foot of Distribution Piping (Line 15)]

(License #)


(Date)(Designer) (Signature)


A. 0

1. If pumping to gravity enter the gallon per minute of the pump: GPM

2. If pumping to pressure, is the pump for the treatment system or the collection system:

0

3. If pumping to a pressurized treatment system, what part or type of system:

4. If pumping to a pressurized distribution system: GPM

(Line 11 of Pressure Distribution or Line 10 of Non-Level or enter if Collection System)

3. ft

4. ft

5.

1. PUMP CAPACITY

Elevation Difference

Additional Head Loss:

Distribution Head Loss:

OSTP Pump Selection Design Worksheet

2. HEAD REQUIREMENTS

NOTE : IF system is an individual subsurface sewage treatment system, complete steps 4 - 9. If system is a Collection System, skip steps 4, 5, 7 and 8 and go to Step 10.

ft (due to special equipment, etc.)

between pump and point of discharge:

Pumping to Gravity or Pressure Distribution:

Soil Treatment Unit Media Filter Other

Collection System

Gravity Pressure

Treatment System

6. A. Supply Pipe Diameter: in

B. Supply Pipe Length: ft

7.

Friction Loss =

8.

ft X 1.25 = ft

9.

ft per 100ft X ft ÷ 100 = ft

Based on Friction Loss in Plastic Pipe per 100ft from Table I:

Calculate Supply Friction Loss by multiplying Friction Loss Per 100ft (Line 6) by the Equivalent Pipe Length (Line 7) and divide by 100.

Determine Equivalent Pipe Length from pump discharge to soil dispersal area discharge point. Estimate by adding 25% to supply pipe length for fitting loss. Supply Pipe Length (5.B) X 1.25 = Equivalent Pipe Length

Supply Friction Loss =

ft per 100ft of pipe

Soil Treatment Unit Media Filter Other

Collection System

Gravity Pressure

Treatment System


OSTP Pump Selection Design Worksheet

10. Equivalent length of pipe fittings.

Quantity X Equivalent Length Factor = Equivalent Length

X =

X =

X =

X =

X =

X =

X =

X =

X =

X =

X =

A. Sum of Equivalent Length due to pipe fittings: ft

B. Total Pipe Length = Supply Pipe Length (5.B) + Equivalent Pipe Length (9.A.)

Hazen-Williams Equation for h

Valve 11

NOTE: System installer should contact system designer if the number of fittings varies from the design to the actual installation.

Section 10 is for Collection Systems ONLY and does NOT need to be completed for individual subsurface sewage treatment systems.

QuantityFitting Type

45 Deg Elbow

90 Deg Elbow

Gate Valve

Equivalent Length Factor

Equivalent Length (ft)

Butterfly Valve

Globe Valve

Angle Valve

Tee - Branch Flow

Tee - Flow Thru

Swing Check Valve

Valve 10

NOTE: Equivalent length values for PVC pipe fittings are based on calculations using the Hazen-Williams Equation. See Advanced Designs for SSTS for equation. Other pipe material may require different equivalent length factors. Verify other equivalent length factors with pipe material manufacturer.

LCQh *)(*5.10 85.1ft + ft = ft

C. Hazen-Williams friction loss due to pipe fittings and supply pipe (hf): Q in gpm L in feet D in inches C = 130

X ( X Total Pipe Length (10.B)

in4.87 ) X ( gpm ÷ 130)1.85 X ft = ft

11.

ft + ft + ft + ft = ft

Total Head requirement is the sum of the Elevation Difference (Line 3), the Distribution Head Loss (Line 4), Additional Head Loss (Line 5), and either Supply Friction Loss (Line 9 ), or Friction Loss from the Supply Pipe and Pipe Fittings for collection systems (Line 10.C)

Pipe Diameter4.87 )

(10.5 ÷


GPM (Line 1 or Line 2) with at least feet of total head.

(10.5 ÷ Flow Rate ÷ Constant)1.85

Pump typeComments:

3. PUMP SELECTION

(Date)

NOTE: Friction Loss from the Supply Pipe and Pipe Fittings (Line 9.C) need ONLY be used if system is a collection system.

(Designer) (Signature) (License #)

NOTE: Supply Friction Loss (Line 8) need ONLY be used if NOT a collection system.

A pump must be selected to deliver at least

LCQD

hf *)(* 85.187.4


DETERMINE AREA AND/OR GALLONS PER INCH

1. A. Rectangle area = Length (L) X Width (W)

ft X ft = ft2

B. Circle area = 3.14r2 (3.14 X radius X radius)

3.14 X 2 ft = ft2

C. Tank model and manufacturer (optional):

C. Get area from manufacturer ft2

D. Get gallons per inch from manufacturer Gallons per inch

2. Calculate Gallons Per Inch :

(Area X 7.48 gallons/ft3)/(12 in/ft) =

ft2 X = Gallons per inch

3. Enter the Pump Tank Capacity (minimum provided in the table below): Gallons

4. Calculate Total Tank Volume

A. Depth from bottom of inlet pipe to tank bottom : in

B. Total Tank Volume = Depth from bottom of inlet pipe (Line 4.A) X Gallons/Inch (Line 2)

in X Gallons Per Inch = Gallons

5. Calculate Volume to Cover Pump (The inlet of the pump must be at least 4-inches from the bottom of

7.48 gal/ft3 ÷ 12 in/ft

TANK CAPACITY

There are 7.48 gallons per cubic foot. Therefore, multiply the area from 1.A, 1.B, or 1.C by 7.48 to determine the gallons per foot the tank holds. Then divide that number by 12 to calculate the gallons per inch.


Width

Length

Radius

5.

(Pump and block height + 2 inches) X Gallons Per Inch (1D or 2)

( in + 2 inches) X Gallons Per Inch = Gallons

6. Gallons

- Line 17 of the Pressure Distribution or Line 11 of Non-level

7. Calculate Maximum Pumpout Volume (25% of Design Flow)

Design Flow: GPD X = Gallons

8. Gallons

9. Calculate Doses Per Day = Design Flow ÷ Dosing Volume

gpd ÷ gal = Doses

10. Calculate Drainback:

A. Diameter of Supply Pipe = inches

B. Length of Supply Pipe = feet

C. Volume of Liquid Per Lineal Foot of Pipe = Gallons/ft

D. Drainback = Length of Supply Pipe X Volume of Liquid Per Lineal Foot of Pipe

ft X gal/ft = Gallons

11. Total Dosing Volume = Dosing Volume (Line 8) plus Drainback (Line 10.D)

gal + gal = Gallons

12. Minimum Alarm Volume = Depth of alarm (2 or 3 inches) X gallons per inch of tank (Line 1 or 2)

in X gal/in = Gallons

Calculate Volume to Cover Pump (The inlet of the pump must be at least 4 inches from the bottom of the pump tank & 2 inches of water covering the pump is recommended)

Minimum Pumpout Volume - 5 X Volume of Distribution Piping:

0.25

DOSING VOLUME

Select a pumpout volume that meets both items above (Line 6 & 7):

Width

Length

Radius



TIMER or DEMAND FLOAT SETTINGS

Select Timer or Demand Dosing: 0

A. Timer Settings

13. Required Flow Rate :

A. From Design (Line 11 of Pressure Distribution or Line 10 of Non-Level*): GPM

B. Or calculated: GPM = Change in Depth (in) x Gallons Per Inch (Line 1 or 2) / Time Interval in Minutes

in X gal/in ÷ min = GPM

14. Choose a Flow Rate from Line 13.A or 13.B above. GPM

15. Calculate TIMER ON setting:

Total Dosing Volume (Line 11)/GPM(Line 14)

gal ÷ gpm = Minutes ON

16. Calculate TIMER OFF setting:

Minutes Per Day (1440)/Doses Per Day (Line 9) - Minutes On (Line 15)

÷ doses/day - min = Minutes OFF

17. Pump Off Float - Measuring from bottom of tank:

Distance to set Pump Off Float=Gallons to Cover Pump (Line 5) / Gallons Per Inch (Line 1 or 2):


18. Alarm Float - Measuring from bottom of tank:

Distance to set Alarm Float = Tank Depth(4A) - Alarm Depth (Line 13)

in - in = inB. DEMAND DOSE FLOAT SETTINGS

18. Calculate Float Separation Distance using Dosing Volume .

Total Dosing Volume (Line 12)/Gallons Per Inch (Line 2)


*Note: This value must be adjusted after field

measurement & calculation.

1440 min

Timer Demand Dose

19. Measuring from bottom of tank:

A. Distance to set Pump Off Float = Pump Height + Block Height (Line 5) + Alarm Depth (Line 13)

in + in = Inches

B.

in + in = Inches

C. Distance to set Alarm Float = Distance to set Pump-On Float (19.B) + Alarm Depth (2-3 inches)

in + in = Inches

in Alarm Depth in

Pump On in

Pump Off in Pump Off in


(License #)

FLOAT SETTINGS

(Date)

TIMED DOSING

Distance to set Pump On Float=Distance to Set Pump-Off Float (Line 19.A) + Float Separation Distance (Line 18)

(Signature)(Designer)

Alarm Depth

DEMAND DOSING


#9: Disinfecti on

A. What is the goal of disinfecti on?

B. Name 4 general types of pathogens: 1)

2)

3) 4)

C. Calculate the volume of the chlorine contact chamber required to provide 30 minutes of contact ti me for an average daily fl ow of 15,000 gallons per day.

D. What are two disadvantages to using chlorine as a method of disinfecti on? 1)

2)

E. Under what conditi ons would you recommend the use of UV disinfecti on? Why?

Advanced Design and - University of Minnesota Wittwer 612-624-7460 [email protected] Workshops, ......

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Transcript of Advanced Design and - University of Minnesota Wittwer 612-624-7460 [email protected] Workshops, ......