wastewater treatment in the land beyond the sewers · wastewater treatment in the land beyond the...

Wastewater Treatment in the Land Beyond the Sewers

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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

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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!

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Effluent Pumping

Intermittent Sand Filter Recirculating Sand Filter

Textile Filter

Advanced treatment options . . .

23

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

66

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

67

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

72

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