Wastewater Treatment in the Land Beyond the Sewers
--
Finding Funds and Design Decisions
Barry Tonning, TetraTech
Tessa Edelen, Kentucky Waterways Alliance
talk overview
• Background on rural wastewater
treatment in Kentucky
• Wastewater treatment options
for unsewered areas
• Potential funding sources
• Onsite and clustered treatment
system case studies
– Bacon Creek
– Olympia / Rose Run
– Hinkston Creek
• Questions and comments
Background on Rural
Wastewater Treatment in KY
In the old days…
4
the stats.
• About 25 percent of the U.S. population relies on
decentralized (or onsite-wastewater) treatment systems.
• About 95 percent of the onsite wastewater disposal
systems are septic systems.
• In Kentucky, it is estimated that almost 50 percent of
households use onsite systems
• In the Green River Basin, it is also about 50 percent of
households on onsite systems.
• Of these approximately 168,172 households not on
sewers, an estimated 13,043 systems are not septic
systems.
*In Kentucky, a failed system is one that
exhibits surfacing of septic effluent.
*Lack of proper maintenance is cited as
the most common reason for system
failure in the state.
Wastewater Treatment Options
For Unsewered Areas
10
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Wastewater pollutants of concern
• Pathogens – bacteria & viruses mainly; plus protozoa, worm eggs
• Nitrogen – causes algal growth in nitrogen-limited (mostly coastal) waters; nitrate can cause “blue baby” syndrome
• Phosphorus – causes algal growth in P-limited (mostly inland fresh) waters
• Others – pharmaceuticals, cleaners, solvents, & other toxics (most of which affect treatment processes)
12
Wastewater treatment options
for unsewered areas
• Individual onsite (“septic”) or advanced
wastewater treatment systems
• Clustered systems
with soil infiltration
or effluent re-use
• “Package” plants with
ditch/stream discharge
• Centralized plant with
lake/river/creek discharge
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Centralized treatment plants
• Most discharge to rivers, lakes, streams, ocean, & need state/federal NPDES permit
• Centralized treatment can
result in better operator
attention and mgmt
• Good option for high-
density development
• Efficiencies related to
economy-of-scale
14
Centralized treatment plants
• Some older plants
have CSOs or SSOs
• Collection systems have
infiltration/inflow & leaks
• New regulations forcing
higher treatment levels
• Upgrades & expanded
collection systems are costly
• Local opposition to siting some new plants
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dispersal
dispersal
dispersal
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Soil-discharging treatment systems
• Good for high or low density areas – Need appropriate space, soils,
geology, & groundwater conditions!
• Excellent treatment performance
• Individual systems – Septic tank with gravity flow
– Tank with pressure dosing
– Advanced systems with dosing
• Clustered systems – Each home usually has a tank
– Effluent collected via gravity or pumped
– Multiple options for treatment facilities
– Dosed or gravity flow dispersal to the soil
17
Decentralized treatment technologies
Treatment process units
• Conventional systems
– Septic tank
– Trenches, chambers, or other
dispersal
• Advanced systems
– Tank or treatment unit
– Fixed film or suspended
growth unit(s)
– Gravity, pumped, pressure
drip (dosed) effluent dispersal
18
Overview of treatment processes
• Bacteria & other pathogens – Biological death, predation, &
decomposition outside host (i.e., in soil)
• Phosphorus – Some retention in tank, soil
adsorption
• Nitrogen – Ammonia nitrified in treatment
unit or soil; poor denitrification of nitrate w/o anaerobic step
• Suspended solids – Settling out in tank & in treatment
unit sludge; filtration by soil
• Other pollutants – Soil treatment removes a variety
of pollutants by chemical, physical, & biological processes
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Conventional gravity-flow “septic” system
Advanced Wastewater
Treatment Options
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Beyond the “box & rocks” systems
• Package & site-built units provide additional treatment for septic tank effluent – Usually requires tank
– Can discharge to soil or surface waters
• Treatment processes include: – Suspended growth biological treatment, followed by settling tank
& disinfection
– Fixed film biological treatment, followed by filtration & drip irrigation to soil
– Includes use of various media
• All treatment systems require professional management!
22
Effluent Pumping
Intermittent Sand Filter Recirculating Sand Filter
Textile Filter
Advanced treatment options . . .
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Some other treatment approaches
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Textile filters installed in series
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Soil dispersal options
28 Source: University of Minnesota Extension
• Drip lines high in the soil profile enhance treatment
• Good for sites with high water tables
• Can be used on sloping sites with trees, etc.
• Excellent dosed dispersal approach
Drip irrigation: new technology
from the agricultural sector
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Clustered treatment systems • Existing development
– Can economically serve
dense areas with small lots*
– Improves treatment levels
over septic system units
– Increases groundwater
recharge & reuse options
• New development – Facilitates development that fits local landscapes and
meets wastewater treatment requirements*
– Very friendly to smart growth, green infrastructure, and low-impact development approaches
– Promotes clustering of homes & businesses, preservation of woodlands & open space
* Need space for soil dispersal area
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Cluster system
basic layout
(OPTIONAL)
Treatment system effectiveness Pollutant
Parameter
Septic
Tank
Effluent
(mg/L)
Aerobic
Treatment
Unit (FIXED
OR SUSP)
(mg/L)
Media
Filter
Treatment
(SINGLE-
PASS)
(mg/L)
Coarse
Media,
Foam or
Textile Unit
(RECIRC
FILTER)
(mg/L)
Removal
Rate (%):
~3’ of Soil
BOD
(mg/l)
100-150 30-50 2-15 5-15 >90%
TN
(mg/l)
40-70 30-50 30-50 20-30 15-20%
TP (mg/l) 5-10 4-8 4-8 4-8 90-100%
Bacteria 106-108 104-106 101-102 102-103 >99.99%
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Average costs of decentralized treatment systems
Funding Options for Projects
USDA Rural Development 504 Repair
Program
• Assistance program for rural, low income communities
• Program participants must be homeowners
• City or municipality must be the applicant (not individuals
or non-profit organizations)
• Low interest loans or grants available
• Loans are more common, and they are offered at 1%
KY Clean Water State Revolving Fund
• Program to provide low interest loans for infrastructure
projects that promote the goals of the Clean Water Act
• To be considered eligible to receive a loan, a project
must be identified on KY’s annual Intended Use Plan List
• Project examples include sewer line extensions, CSO
elimination, new WWTP, wet weather storage tank, and
others
• Example Centertown Liftstation Rebuild Project: to
reduce I&I as well as replace cracked liftstations that
have the potential to leak untreated sewage
37
KY DOW Nonpoint Source Grants
• Grants can be obtained to implement a watershed plan,
including onsite wastewater programs (not sewer)
• Cash or In-kind Match requirement
• Grant management can be challenging
• Deadline for preliminary application is usually in
February (so you missed this year)
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Eastern KY PRIDE
Case Studies
• Bacon Creek
• Olympia / Rose Run
• Hinkston Creek
• Skaneateles Lake
• Others
Bacon Creek Project
• DOW 319 implementation grant with
Bacon Creek Watershed Council
• Bacon Creek has bacteria issues
• MST data collected
in 2010 indicate both
human and animal
sources
43
Project Outcomes
• Completed 13 Septic Tank Pump Outs
• Completed 6 Septic System Installations
• Had many more applications for the repair
and replacement program = ongoing need
• Local partners are very important
44
Sanitation District Management of
Repaired/Replaced Individual and Clustered
Wastewater Treatment Systems
in Olympia, Kentucky
Celia O. Barker, Bath County Health Department
Jeffrey Brittingham and Barry Tonning, Tetra Tech
Project location: Olympia,
Kentucky
Targeted
Project Area in
central Bath
County
Why Bath County?
US EPA Region 4
“Straight Pipes”
report targeted
Bath, Harlan, and
Martin counties
“The widespread
scale of both the straight
pipe issues as well as
package plant wastewater
problems present an
environmental crisis
which deserves attention
from all levels of
government.”
Community overview
• Rose Run Creek contaminated by bacteria and
possibly nutrients
• Rose Run flows into Slate Creek, which is
impaired for high bacterial levels
• Sewage observed in the roadside ditches in the
Olympia community
• Approximately 70-80 homes and 6-9 businesses
are located in the community
• Low-income area in low-income county
Rose Run
Creek
Landscape view of Olympia area
Olympia aerial view Rose Run
Creek
Project overview
• Survey and assess existing wastewater
treatment systems
• Develop appropriate treatment options
– Individual system repair/replacement
– New cluster systems where appropriate
– All discharges were to the soil (KY DOH permit)
• Design treatment systems
• Install systems – Project completed in 2011
Soil-discharging systems
• Individual systems
– Septic tank with gravity flow
– Tank with pressure dosing to uphill drainfield
• Clustered systems
– Each home has a tank
– Effluent collected via gravity or pumped
– Soil treatment area acquired via easements (donated and purchased)
Cluster System Layout
“Frog Bottom”
Tackett Property
Final project tally
• 55 individual homes served
• 5 cluster systems – 3 for two homes, one for 4 homes, one for a church & 2 homes
• 2 existing system repairs
• Average cost was approximately $7,500
• Higher than usual due to challenging conditions, lots of imported soil
Project funding and support
• KY Division of Water Clean Water Act
Section 319 (Nonpoint Source - $567,000)
• Matching support from resident fees,
BCHD, system installers, others (In-Kind)
• Possibility of additional support for more
system replacements via the Stimulus Bill!
Project partners
• Bath County Health Department
• Gateway District Health Department
• Bath County Sanitation District
• Gateway Area Development District
• Bath County Fiscal Court
• National Small Flows Clearinghouse
• Tetra Tech
Challenges encountered
• High monthly fee for advanced treatment cluster system exceeded local budgets
• Poor soil and shallow groundwater = some fill for drainfields, clustering, pumping
• Easements for some clusters took negotiation and patience!
• Streamlining payment for installation contractors was necessary . . .
Treatment system management
• All systems permitted by Bath
County Health Dept.
• BCSD tap-on fee is $500;
waived to $100 for Olympia –
Rose Run Project participants
• Quarterly service fee paid by
residents set by Bath County
Sanitation District at $25
• Sanitation district will inspect
and manage all systems,
including tank pumpouts
Leaching Chamber
Installation – Vance
Property
Bacteria sampling in Rose Run
• E. coli = 1220 CFUs in Rose Run at McCarty Branch bridge in October 2008, prior to replacement of 4 systems in that area
• Blackwater pool present during summer and fall of 2008 slowly disappeared after system replacement
• Follow-up sampling showed bacteria reductions in 2009
Hinkston Creek Impairments
• Several sections have poor water quality
along the mainstem of Hinkston, plus
Black’s Creek, Grassy Lick, Boone Creek
• Impairments include:
– E. coli bacteria
– Siltation & sedimentation
– Poor habitat conditions
– Excess nitrogen
Major findings
• E. coli bacteria exceeds the
benchmark annual value (8.0E+09
CFU/acre/year)
• Total nitrogen loading exceeds the
benchmark value (4.1 lb/acre/year)
• Total suspended solids exceed the
benchmark value (40.8 lb/acre/year)
• Phosphorus loading rates are
generally within the benchmark
loading rate of 0.5 lb/acre/year.
• Storm flow sampling would likely
show higher values for pollutants at
most locations
Septic system cost-share
• Installed 5 new wastewater
treatment systems
• Project paid 75%
• Owner paid 25%
• Designed/permitted by
county health departments
• All were conventional type
systems (tank/drainfield)
• Average cost ~ $4,900 65
Lake Carnico Kentucky
• 114 acre lake, created in 1962
• 103 homes built around lake shore
• Septic systems, holding tanks, pkg plants
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System details
• $2.7 million cluster system built in 2013
• Pumped collection system (design = 165 homes)
• Recirculating gravel filter (95 ft x 50 ft)
– 900 dump truck loads imported soil
– UV light disinfection
– Drip tube dispersal (16.5 mi)
• Funded by:
– $1.5 m grant, $550k loan (2% for 20 yrs), $4k
assessment on each house, $500 per vacant lot, $70
per month fee (vs. $160/mo for pumping tanks)
– Managed by SD2 in Nicholas County
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Bethel Heights, Arkansas • Rapidly-growing population relied on
individual septic systems
• State law allowing property owners to de-annex from one city and annex to another if their city could not provide wastewater service.
– City lost tax revenue as residents exercised their right to de-annex.
• City selected two cluster systems phased in to meet increasing demand as the City’s population grew.
– Septic tank effluent pump (STEP)
– Modular geotextile packed bed filters
– Effluent dispersal via drip tubing to irrigate hay fields (hay is cut and shipped out of nutrient-rich watershed)
– One system irrigates a park and along walking trails.
MAWSS, Mobile, AL
• Service area: 233 mi2 includes ~1,300 mi. of gravity sewers, ~200 lift stations, ~120 miles of force main
• MAWSS owns and operates (EPA Level V RME) two conventional and at least 12 decentralized wastewater facilities
• On-site treatment/dispersal in Tricentennial Park adjacent to Three Mile Creek
– Demonstrate use of decentralized facilities within centralized infrastructure
– Wastewater mined from sewer line and treated using one of three different decentralized systems
– Treated effluent is distributed through subsurface drip irrigation system to nourish the grass and shrubs in the park
Skaneateles Lake NY
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General management approach
• Management intensity is tied to risk
– Sensitivity of receiving water, local setting
– Complexity & density of treatment systems
• Public or private mgmt entity is necessary!
– Sanitation districts
– Public utility
– Special district
– Profit/nonprofit corporation
• Public agencies provide
regulatory oversight
Use of Remote Sensing Tools
• GIS mapping
• Aerial
photography
• Tailored
analysis
Identify
high-risk
areas
Identify pollutant
sources and
target
management
practices
Onsite wastewater system risk analysis
Riparian buffer assessment and
deficiency analysis
High-risk stream channel
assessment
Outline
Onsite Wastewater System Risk Analysis
► Failing septic systems are a concern for nonpoint source (NPS) pollution in the watershed
http://www.pumperguys.com/septic-installation.php
Onsite Wastewater System Risk Analysis
► Area of interest:
Exclude publicly serviced areas
Include areas within 1-2 miles of publicly serviced areas where >1house/acre
► Spatial attributes:
Household density
Closeness to streams
Closeness to karst topography
Aarons R
un
Lane Branch
Som
erset
Cre
ek
Judy
Mount Sterling
Gra
ssy L
ick C
reek
Plum
Lic
k Cre
ek
Hinkston CreekWatershed
NAD_1983_State_Plane_Kentucky_FIPS_1600Map produced 03-08-2012 - C. Carter
Legend
Sewer Line
Publicly Serviced Area
Buffer (2 miles)
0 1 20.5Miles
0 1 20.5Kilometers
Hin
ksto
n C
reek
Hinkston CreekWatershed
Onsite Wastewater System Risk Analysis: Data
► Areas serviced by centralized wastewater treatment
Water Resources Information System, which is supported by the Kentucky’s Area Development District and KDOW
► Household density
U.S. Census Bureau’s 2000 Census Block data
► Closeness to streams
High resolution streams data layer created by the United States Geological Survey (USGS) as part of the National Hydrography Dataset
► Closeness to Karst topography
Geologic data layer developed by the Kentucky Geological Survey
Onsite Wastewater System Risk Analysis
► Prioritization and Results
Applied equal weight to each of the three attributes
Areas with highest potential to contribute NPS pollution to streams and/or near-surface groundwater
► Subsequent analyses
► Target for management
Aarons R
un
Lane Branch
Som
erset
Cre
ek
Judy
Mount Sterling
Gra
ssy L
ick C
reek
Plum
Lic
k Cre
ek
Hinkston CreekWatershed
NAD_1983_State_Plane_Kentucky_FIPS_1600Map produced 03-08-2012 - C. Carter
Legend
Sewer Line
Publicly Serviced Area
Buffer (2 miles)
0 1 20.5Miles
0 1 20.5Kilometers
Hin
ksto
n C
reek
Hinkston CreekWatershed
Priority Septic Area
Med. Priority
High Priority
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