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Mounds. Where soils are rocky or tight or the water table is high, a mound can be created

with fill material. The wastewater from a septic.or aerobic’ tank is allowed to seep through
the soil in the mound, which provides the treatment. |

Mound System Sat

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Rock Bed
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Septic tank Pumping chamber

E-T Beds. An evapo-transpiration (E-T) bed is similar to a mound but relies more on the
evaporation of the wastewater through the bed and plant cover.

Sand Filters. Still another system which uses a septic or aerobic tankis a sand filter. Atwo

to three foot bed of sand installed in the ground filters the wastewater from the tank. The
filtered wastewater can be disposed through the soil or discharged to astream. Some States
require disinfection before stream discharge. i

Alternative Sewers

Since conventional sewers are usually by far the major capital cost item of a wastewater system,
alternative sewers should be carefully considered. Alternative sewers are smaller in size and
are installed at shallow depths. Since they have no manholes and fewer joints, much less rain
and ground water gets into alternative sewers so treatment plants can be smaller. One or more
of the following alternative sewers are generally better sitited for small communities than
conventional sewers.

Small Diameter Gravity Sewers. Smal! diameter gravity sewers carry septic tank effluent. The
pipes, which are usually plastic, can be small (4 inches iri diameter) and placed at less slope
than a conventional sewer. Operation and maintenance requirements are low.



United States
Environmental Protection
Agency’

Office of Water
Program Operations
Washington DC 20460

Official Business
Penalty for Private Use
$300



What To Do If Reduce Project Scope. If the project you are planning is too costly, it may be possible to reduce i
Sewers Or its size. Take a hard look at the population projections and flow estimates. Be realistic about
estimates of future growth and wastewater treatment needs and reevaluate the extent of

Treatment Facilities sewering you propose. Can some pipes be eliminated by using onsite or cluster systems in

Are Too Expensive outlying areas? A water conservation program may reduce wastewater flow and the size of
the proposed treatment plant. Italso may allow continued use of onsite systems. Another idea :
for communities expecting high growth is to construct the facilities in stages to spread out
your town’s investment over a longer time period.

Simplify Design. Often there are ways to simplify the design of facilities to cut costs and make
operation easier. Make sure the layout ofthe plantis as efficient as possible and eliminate all
non-essential features such as brick veneer walls on buildings and paved roads with curbs and
gutters. Perhaps laboratory or other facilities, and even plant operators, could be shared with

a neighboring town.

Improve Financing. Sometimes the cost to finance a project can be reduced. Be certain that
all potential funding sources for the project have been considered. Some Federal and State
agencies have low interest loans. To reduce interest rates, some States have bond banks or
will guarantee local bonds. In some cases, extending the bond life can reduce annual costs.
Your State water quality officials or Regional EPA staff may know of some innovative financing
methods that could save you money.

Have You Chosen Astandard wastewater treatment facility may not be the best solution for your small community

An Appropriate situation. A combination of approaches may be needed to solve different wastewater problems

Technology? within the community. One or more of the technologies described below may be the most
SY appropriate for your community. All are proven technologies currently being used successfully

across the country.

Onsite Systems |

Some communities have avoided sewers altogether by using systems thattreatthe wastewater |
at each homesite. Properly installed and maintained onsite systems will operate satisfactorily
for twenty years or more in areas where site conditions are suitable. A management district
can be set up to oversee operations.

i

i
Septic Systems. The most common onsite system is the septic tank, soil absorption system. |
This simple method settles out solids in a buried tank, which is cleaned every 3 to 5 years. | |}
Liquid flows from the tank to a drainage bed ortrench and filters into the soil through perforated | ||

pipes. ' {

Alternative Onsite Systems. Several different types of onsite systems have been developed « i
to operate in situations not suitable for conventional septic systems such as steep slopes, rocky a
or tight soils and high groundwater. : |

Aerobic System. This variation uses an aerobic tank instead of a septic tank to mix aif with
the wastewater for additional treatment before disposal.

Dosing. Some systems use a leaching bed or trench but pump the wastewater in measured
doses to allow a more even flow over the entire distribution area. |

Alternating Beds. If space is available, two alternating absorption fieldscanbeusedsoone |
can have time to recover its ability to absorb wastes: ia
t



Pressure Sewers. Pressure sewer systems use a small pump at each house to move wastewater
under pressure through small diameter plastic pipes to a treatment facility or a larger interceptor
sewer. The pumps are of two types. Grinder pumps are housed in basement or underground
tanks and grind the raw sewage while pumping it. The other type is the septic tank effluent
pumping system, called STEP. STEP systems have less expensive pumps and have fewer
problems with grease buildup than grinder pump systems.

Pressure Sewer System

Pressure main

<=(__)Septic tank with effluent pump

Vacuum Sewers. In a vacuum sewer system, wastewater from each home is drawn through
small collector pipes to a central collection station by vacuum. The vacuum collection station
houses a pump which delivers the wastewater to the treatment facility or an interceptor sewer.
Wastewater entry into the system is controlled by vacuum valves at each home or at groups
of homes. Because of their limited ability to lift wastewater, vacuum sewers are best suited to
flat areas where gravity sewers would be too expensive.

Cluster Systems

Where conditions are not suitable for onsite systems, cluster systems can be used. The most
common form uses alternative sewers to transport either septic tank effluent from several :
houses to a common drainfield, or raw wastewater from several houses to a common septic
tank followed by disposal. Treatment can also be provided by a pond, sand filter, mound or |
land application. Typically each cluster system serves a group of two or more homes but less :
than an entire community.

Cluster System

Small
diameter
sewers

eT aT aT

Drainfield

Dosing chamber a ae Ae aor


|.

Is Your Proposed |
stewater Project

Wa

SEPA

Too Costly?
| Options for

Small Communities



Low Cost Centralized Treatment

Some simple and reliable centralized treatment systems that are well suited to small community

situations are ponds, lagoons, trickling filters, oxidation ditches and overland flow land

treatment. All are well established methods for providing standard levels of treatment or better.
In general, they cost less to build and run than the commcn method of treatment called activated

sludge. They also use less energy and are easier to operate and maintains

If your community is starting to plan a wastewater project, make sure the engineer you choose
has experience with these small community technologies. if your ongoing project does not

| Trickling Filter

consider these technologies, a reevaluation of alternatives may be in order.

\
Putting in a wastewater system that effectively and reliably does the job, yet doesn’t financially
strap the community, is a challenge. This challenge can be met by making careful choices to

keep down the cost of construction, operation, mainterlance and financing.

MORE INFORMATION FROM

EPA National Small Wastewater Flows
Clearinghouse

West Virginia University; Morgantown, WV
26508; 800-624-8301

Center for Environmental Research
Information

26 W. St. Clair; Cincinnati, OH 45268;
513-684-7391

EPA publications (call 202-382-7373)

—Small Wastewater Systems-Al-
ternative Systems for Small
Communities and Rural Areas,
FRD-10

—Emerging Technology series of
foldouts

—Less Costly Wastewater Treatment
Your Town

—Financial Capability Summary
Foldout—A Simplified Approach

© . Your EPA Regional Office

1. Boston

(CT, ME, MA, NH, Rl, VT); JFK Federal Bldg.;
Boston, MA 02203; 617-223-7210

2. New York

(NJ, NY, PR, Vi); 26 Federal Plaza; New York,
NY 10007; 212-264-2525

3. Philadelp!
(DE, MD., PA, VA, WV, DC);6th & Wainut Sts.;
Philadelphia, PA 19108; 218-597-9814,

4. Atlanta” .

{AL, GA, FL, MS, NC, SC, TN, KY); 345 Courtland
St, N.E.; Atlanta, GA 30308; 404-881-4727

5, Chicago .

(MI, WI, MN, IL, IN, OH}; 230 S. Dearborn St.;
Chicago, IL 60604;, 312-353-2000

6. Dallas
(TX, OK, AR, LA, NM);
1201 Elm St.; Dallas, TX 75270; 214-767-2600

7. Kansas City
{KS, NE, 1A, MO); 324 E, 11th St.; Kansas City,
MO 64108; 816-374-5493

8. Denver ;
(CO, MT, WY, UT, ND, SD); 1860 Lincoln St.;
Denver, CO 80203; 303-837-3895.

9. San Francisco

(CA, AZ, NV, HI, GU, American Samoa, Trust
{Territories of the Pacific);215 Fremont St,; San
Francisco, CA 94105; 415-974-8088

10. Seattle
(WA, OR, 1D, AK); 1200-6th Ave.; Seattle, WA
98101; 206-442-5810.

EPA does not endorse, approve, or
disapprove any system described here.
Notall systems shown are approved by
all jurisdictions. To get EPA funds, a
project must meet Federal, State, and
local standards.



Wastewater
Facilities

For Small
Communities
A Tall Order

The Small
Community
Dilemma

Providing wastewater treatment facilities to small communities is by no means a small task. ,
According to a 1982 survey, small communities with populations less than 10,000 need more !
than $13 billion to comply with the Clean Water Act. Of this, $9 billion is for new sewers and)
$4 billion is for treatment plants. Clearly, clean water for the nation is essential, but expensive. :

Some small community residents may have trouble understanding why large increases in their |
sewer bills are necessary, especially if their rates have been low in the past. Your existing |
facilities were likely built years ago when everything was less expensive. Perhaps the loan or L
bonds used to finance them have been paid off or are being paid through other means, such :
as property taxes. The only cost you may be paying now is for operation and maintenance. i
More importantly, old wastewater plants probably do not provide the high level of treatment;
needed to clean up the waters. Better treatment facilities to meet our clean water goals simply
cost more to build and run. Therefore, your increased sewer bill may be a reasonable i
price for the benefits to your community — cleaner water, better fishing and swimming, |
and a healthier environment.

Most small communities find it difficultto afford conventional sewers and wastewater treatment
plants. Since 1972, the U.S. Environmental Protection Agency (EPA) has paid 75% of the '
construction costs for most wastewater facilities. Beginning in October 1984, however, the EPA |
share will be reduced to 55%, and less EPA funding will be available for constructing collector
sewers. States and local communities must assume a larger share of the cost of clean water.

Whatwill this mean to small towns that need new or improved wastewater treatment facilities?
Is it possible to reduce the financial burden without reducing the quality of treatment?

Higher Costs Because of their size and layout, small communities face a heavier cost burden ;
in building wastewater systems. Their size does not allow them to enjoy the economies of |
building large facilities. In other words, sewers and treatment plants cost more per house in
a small town. Adding to this problem is the fact that a rural population is spread out, which’
means longer sewers are needed to serve each house. It costs twice as much per house to H

sewer a town of 3,500 than a city of 100,000 and three times as much for a town of 500.

Relative Cost Of Sewering By Size Of Community

$

Pop. = 100,000 . Pop: =

Harder to Raise Capital. In addition to higher costs, smaller communities have more difficulty ‘
financing their facilities. Some common financial problems include:

Lower Income - In general, annual incomes of rural households are about $3,000 less' ti
than urban households. oo . |

@ Dependence on Residential Tax Base - Since there may be only a few commercial or?
industrial revenue sources in a small community, the homeowner often shoulders a ¢
greater share of the tax burden. ene

@ Difficult Financing - Smaller communities often have difficulty qualifying forthe bond
market. Those that do usually have a low bond rating. Further, a small community is
likely to pay a higher interest rate because of the smaller amount of the bond.



— —+
Management Problems. Most small towns have the rescurces and ex,

simple wastewater systems. They seldom can getthe skilled
management, construction supervision, billing, accountin
maintenance necessary for a sophisticated treatment plant.

As you can see, selectin
maintaining the necessa
small community. |
|
i
|

Choose
Appropriate
Technologies,

How do you solve this dilemma? First, it’s vital to kee
to reduce wastewater facility costs is to
community situation —a system that is si
can mean simply modifying or upgrading the facilities you Ha
If the cost of new sewers is a problem,
types of small diameter sewers, maintain
onsite systems where septic systems a!
flow to a suitable neighborhood treatment site,
work properly. Appropriate systems for central
flow, trickling filters and oxidation ditches. T!
are described more fully in the last section

Pp

mple and inexpensi'

ing and upgrading|s.

can also beus:

Has Your
Community
Selected A Project
With Reasonable
Costs?

EPA has developeda screening system to hel
treatment option. The system is based onan anal
survey of needs in the construction grants
community identify problems at an earl

program. The pur}
ly stage when they

The EPA screening system consists of six financial indi
Part A measures the reasonableness of your project's
experience. The cost indicators reflect what your com
without funding. Part B is ameasure of the net cost of th
These costs assume a 25% local share of the project capital ct
parts of the country, your State’s screening program may

Part A-Project Capital Costs An

Indicator

re-unsuitable. Cluster s\

‘pertise to manage only

personnel needed for the project

|, budgeting, opetations and

g a wastewater treatment option, finding the best financial plan, and
ry expertise to manage the system are extremely difficult jobs for a

costs down. The most important way
choose the appropriate technology for your small

iver
ive:

to operate. In many cases this
now, especially onsite systems.

your community should strongly consider different

eptic systems, or using alternative
ystems, which take septic tank
ec where onsite systems won’t

ized treatment include ponds, lagoons, overland
hese appropriate
of this. pamphlet.

‘small community technologies

|
p ensure selection of an appropriate wastewater
ysis of thousands of projects in EPA’s biennial

ose of this system is to help your
can be more easily resolved.

icators and has two parts (see below).
costs and sizing based on national

1 project to the existing households.

st. Since costs vary in different

use different criteria.

id Sizing

Suggested Criteria

Capital Cost of Sewers " $ 4000 per household

Capital Cost of Treatment $ 3 per gallon per day of capacity
Total Project Capital Cost $ 6000 per household
Allowance for Future Flow 50% of initial flow

Part B-Cost to the Resident
are ost to the Residential!
Indicator

” $10¢
1.5%

Annual Operations and Maintenance Cost
Annual Household Cost

The values of these indicators for your project are compared t
data or to your State's criteria. Both parts of the screening sys!
cost of the project and its net cost to each household must be \

Project exceeds the criteria for any of the indicators in Part
y proble

with you to take a closer look at your project so that an’
Contact your State officials for more information.

Customer

Suggested Criteria

per household
of median household income

othe criteria based on national

tem are important; both the total
ithin acceptable limits. If your

A or Part B, your State will work

ms can be analyzed and resolved.