On-Site Sewage Program
The purpose of this program is to
permit, inspect and investigate complaints associated with on-site sewage
systems. Anyone who installs, alters or repairs an on-site sewage system is
required to first obtain a permit from the Benton-Franklin Health District.
Installation of a system requires site and soil evaluations to prevent
environmental contamination.
We also maintain records of existing on-site sewage systems for your
convenience. To assist in this process, please have your address, legal
description of your parcel and tax ID number available.
Construction
of on-site sewage systems
The
permitting process
Location
of on-site sewage systems
Existing
System Evaluations
Other
on-site system questions:
Maintenance
of your system
How do I get a permit to install a new on-site sewage
system? -TOP-
The first step in the process is to
fill out an application. To download an application to install a new system click here. The owner of the property must sign the application and we
must have an original signature (we do not accept faxes).
On the back of the application or on a separate sheet of paper, submit a site
plan and system design.
A site plan will show where you plan on locating your home, driveway or patio,
outbuildings or in ground pools. It must also show the existing roads,
structures on the property and slope of the land. In addition, you will need to
show the location of any wells - yours or your neighbor's. Please see the chart
below for the setbacks you will need to maintain when planning your on-site
septic system.
The system design will show the proposed location of the septic tank,
drainfield and replacement drainfield area. The replacement drainfield area is
equal to the size of the original drainfield and must be kept free from driveways,
roads, buildings, patios, swimming pools, etc.
The minimum size of a drainfield for a residential system is no less than 330
square feet. A drainfield is measured by the length of the drainline
(varies depending on the soil type) multiplied by the width of the drainline (3 feet), then multiplied by the number of drainlines. The number of drainlines
will vary depending on number of bedrooms in the home. Drainlines
are set a minimum of 10 feet apart, center to center.
Since the soil types may not be known at the time you are drawing up your site
plan and system design, use one 55' line for each bedroom in your home, with a
minimum of two lines (2 bedroom home), If your lot is in an established
subdivision you may wish to contact this office to inquire about soil
conditions and if sizing requirements may be known. Once the test holes are dug
(click
here for more information on testholes) your proposed system may need to be modified. Your
inspector will work with you regarding any changes that are needed.
An example of the site plan and system design is shown below and to the right:(click to enlarge)
Include the following on your site plan:
- All buildings, size and location
- Driveways and patios
- Water systems and pipes
- Property size, lines
- Adjacent roads, street names
- Surface drainage
- Bodies of water within 100 feet
- Proposed septic system layout, including the reserve
location and design
- Slope of the land
- All wells within 150 feet
- All easements and restrictions limiting the site's
development
|
When drawing out your site plan,
keep in mind the following set-back requirements:
|
|
Separation Requirements From
|
To Septic Tank
|
To Drainfield
|
|
Public Water Supply Well
|
100 ft.
|
100 ft.
|
|
Private Water Supply (Well or
Suction Line)
|
50 ft.
|
100 ft.
|
|
Water Supply Line (Under Pressure)
|
10 ft.
|
10 ft.
|
|
Surface Water (Lakes, Streams,
Rivers, Ponds)
|
50 ft
|
100 ft.
|
|
Buildings (Including Patios)
|
5 ft.
|
10 ft.
|
|
Property Lines
|
5 ft.
|
5 ft.
|
|
Cuts (Downhill Side)
|
N/A
|
25a ft. or 50a
ft.
|
|
Driveways, Roads
|
5 ft.
|
10 ft.
|
|
Trees
|
5 ft.
|
10 ft.
|
|
Natural Drainage
|
15b ft. +
easement
|
15b ft. +
easement
|
|
Irrigation Well
|
50 ft.
|
100 ft.
|
|
Irrigation Canals
|
50 ft.
|
100 ft.
|
|
aDependent
upon soil conditions on the site.
bSetback
for natural drainage areas shall be measured from the near side high water
mark as determined by 100-year storm analysis. Setback shall be 15 ft. + the
height of cut or bank from the easement edge. The 100-year storm analysis
will determine the easement.
|
Sizing your system:
-TOP-
There are two main components of
your system that must meet sizing requirements: the septic tank and the
drainfield. The size of these components is based on the number of bedrooms in
your home and the type of soils present in the location of the drainfield.
|
Septic Tank:
|
|
2-4 bedrooms
|
1000 gallon tank
|
|
5+ bedrooms
|
250 gallons per bedroom (5 bedroom
= 1250 gallon tank)
|
If you have a garbage disposal
installed in your home, you will need to increase the size of the septic tank
by 250 gallons.
Drainfield:
To properly size your drainfield, we
must determine the type of soils available on your property. This is done by
digging a test hole 8-10 feet deep and looking at the type of soils present,
distance to groundwater and presence of any restrictive layers, such as caliche or basalt. The type of soil present determines the
square feet of drainfield needed times the number of bedrooms. The square feet
of drainfield needed varies depending on the soil
type. Your inspector will help you determine the size of drainfield needed.
Once you have completed the application and site plan, submit these documents
and the appropriate fee to:
Benton-Franklin Health District
7102 W Okanogan Pl
Kennewick, WA 99336
Business Hours:
8:00 a.m. to noon
1:00 to 5:00 p.m.
If you need further assistance, please give us a call at (509) 460 4205.
The permitting process. -TOP-
Once the application and fee are received in our office, you
will receive a phone call from the inspector who will be working with you. This
call will set up a time for the inspector to come out and physically inspect
the property. Depending on the records that we have regarding the soil types on
the property, you may need to arrange for a backhoe to meet the inspector at
the property so that test holes may be dug.
A test hole is
dug 8-10 feet deep. It will show the type of soils on the property, whether or
not ground water is present, or if any restrictive layers are present. It is
best to arrange for a backhoe to be at the site at the same time as the
inspector so that if one hole does not show acceptable soils, another can be
dug easily in another place. It is your responsibility to arrange for the
backhoe and insure that test
holes are constructed and maintained in a manner to prevent injury as required
by chapter 296-155 WAC.
If the acceptable site for the
septic system has been relocated from the original plans, a new site plan must
be drawn up. You will need to sign off on this revision. Once this is done,
the permit is issued. Once issued, the permit is good for one year.
Depending on the schedule of your inspector, the permitting process takes approximately
3 weeks.
How
do I get a permit to repair or alter an already existing
system?
If your system is failing (click
here for signs of a failing system),
the first step you need to take is to obtain a permit to repair it. You may
download the application by clicking here. Submit the application and appropriate fee to the
Benton-Franklin Health District. An inspector will contact you as soon as
possible to set up a time to come out and physically inspect the property and
discuss repair options. The need for a test hole will be discussed at this
time.
How
much does the permit cost? -TOP-
|
New Residential System
|
$495.00
|
|
Non-Residential System. <500
gal.
|
$594.00
|
|
Non-Residential System >500
gal.
|
$990.00
|
|
Residential repair
|
$148.00(one component)/$198.00
(two components)
|
|
Non-Residential repair
|
$594.00
|
|
Residential alteration
|
$495.00
|
|
Permit Renewal
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$198.00
|
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Alternative system plan review
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$297.00 + system application fee
|
Final Inspection. -TOP-
After the installer has put in your
system and before the system has been backfilled, you or the installer will
need to contact the Health District to arrange for a final inspection. This is
done by filling out a Request for Final Inspection form. Click here for the Request for a Final Inspection form. To submit your
request via e-mail Click here. Once the system passes the final inspection, it is ready
for use. A copy of the "as-built" showing the final location of the
system will be mailed to you and the original will be kept on file at the
Health District.
Who can install an on-site sewage system? -TOP-
The homeowner has the option to
install the on-site septic system if it is a non-engineered septic system, or
can choose to hire a licensed installer.
A licensed installer must install your system if it is required to be an
engineered septic system. Click here for a list of licensed installers in Benton and Franklin
Counties.
Where is
my on-site sewage system located? -TOP-
Every owner of an on-site sewage
system needs to know where the on-site sewage system is located in order to
properly maintain it. Pumpers may charge you extra to locate and/or dig up the
lids to the septic tank so that they are able to pump the septic tank. If you
do not know where your system is located, you may be able to obtain this
information from our offices. This document is called an "as-built,"
and it is a drawing of the location of your system when it was inspected by our
office after it was completed.
As built: -TOP-
You may request a copy of your as-built (the drawing of the
location of your septic system on your property) by completing the online form,
coming into our offices, or calling us at (509) 460 4205. Regardless of the
method you use to request this document, you will need to provide the following
information:
Required Information: Name of property owners(s):
Tax Parcel ID#:
Physical address of the system or road name*:
*If your address was once a
"route #, box #" please include the roads/streets that the property
is located on and by. For example, "the property is on 30th Avenue between
Spruce and Verbena." Requestor Name:
Requestor phone number: (So we call you if there is a question or need for more
information.)
How would you like to receive your "as-built":
(1)Mail? Please list your mailing address.
(2)I will pick it up. (3)Phone number:
PLEASE NOTE: Before 1975, permits were not required by law. If your
system was installed before 1975, no records may be available.
Locating your system.
If your system was installed before
1975 and no records are available, here are some tips to help you locate your
system:
- The average size of a 1000 gallon tank is 5'x8'.
- Most tanks are covered by 12 to 18" of soil.
- Tanks installed after 1976 are two compartment tanks
and both compartments will need to be pumped out.
- The lids on the tank are circular, 20"-24" in
diameter and 5'-5 ½' apart.
- You may be able to use a metal detector to help you
locate the tanks as they are made of concrete with rebar, and the handles
on the lids are usually made of metal wire.
Why do I need a permit to build an addition to my home, a
garage or shop, add a pool, patio, etc.? -TOP-
Changes made on your property can
affect the life of your on-site sewage system, reducing the return on your
investment, and the ability to market the property later.
The original septic tank and drainfield were sized according to the number of
bedrooms in the home at the time of installation and the location of the home
on the property. Adding more bedrooms increases the number of people that can
live in the home. More people living in the home adds
to the amount of water and sewage entering your system, putting more of a load
on the system, which decreases its life. Adding rooms, additions, garages,
shops, etc. to your home/property may change the setback requirements for your
system, as well as use up space already set aside as a reserve area for the
drainfield.
An inspector will review the records and conduct an on-site evaluation to make
sure that the system is still sized correctly for the home, that any additional
buildings and/or roads or driveways will stay within the required setbacks, and
that the reserve area for the drainfield is still intact.
To download an application for the "Existing System Evaluation," click here. Once the application is completed and submitted to our
office with the appropriate fee, an inspector will contact you about conducting
a site evaluation and any further information they may need. Part of this
process requires that the septic tank be pumped within the past 3 years. If you
have not pumped your tank within the past 3 years you will need to do so. The
inspector will want to be at your property while this is being done. If you
have had the tank pumped recently, please have the receipt from the pumper
available for inspection. This process takes approximately 1-2 weeks.
I am replacing the home on my property with a new one, what
do I need? -TOP-
You will need to do an "Existing
System Evaluation." This process makes sure that the existing system is
sized appropriately for the new home (the number of bedrooms in the new home is
the same as the old home) and that the placement of the home on the property
does not interfere with the setback requirements or reserve area for the
drainfield.
To download an application for this process, click here. Once the application is completed and submitted to our
office with the appropriate fee, an inspector will contact you about conducting
a site evaluation and any further information they may need. Part of this
process requires that the septic tank be pumped within the past 3 years. If you
have not pumped your tank within the past 3 years you will need to do so. The
inspector will want to be at your property while this is being done. If you
have had the tank pumped, please have the receipt from the pumper available for
inspection. This process takes approximately 1-2 weeks.
How do I have my system evaluated for mortgage purposes? -TOP-
If you need to have your system
evaluated in order to sell or refinance your property, click here to download an application for a mortgage certification.
This process consists of:
- Reviewing the records on file for the system,
- Performing a site visit to verify that water in the
home drains properly, that there are no obvious malfunctions of the system
by backups or surfacing in the yard,
- Commenting on any encumbrances to the systems (i.e.,
swimming pools, patios, trees),
- Commenting on suitable replacement area or
availability,
- Verifying and commenting on horizontal setbacks,
- Comment on the age of the system if over ten years old;
and
- Verifying that the number of bedrooms in the home
matches the design of the existing system.
Once the application and fee is
received in this office, the process will take approximately 1-2 weeks.
What if my property will not allow for a conventional
gravity flow system? -TOP-
We make every effort to find an
acceptable location to install a conventional gravity flow system, however, in
some cases the soil types are not suitable, a restrictive layer is present or
groundwater is too close to the surface for this type of system. In these cases
an engineered system may be required. The inspector will advise you what type
of alternative system you will need. For more information the types of
alternative systems available, click here. There is an additional fee of $297.00 required to review
the system design. You will also need to hire an engineer or licensed septic
designer to design the system for you. Click
here for a list of professional
engineers and licensed on-site septic system designers.
Maintenance
of your system
Protect your Investment Video
How does a septic system work? -TOP-
First, household wastewater flows
into the septic tank. In the tank, heavy solids settle to the bottom forming a
layer of sludge, while grease and light solids float to the top forming a scum
layer. As more wastewater enters the septic tank from the house, the separated
wastewater in the middle layer of the tank is either pushed out or pumped into
the drainfield. Microorganisms living within the drainfield consume leftover
waste particles and harmful germs and viruses.
The sludge and scum layers remain in the tank where naturally-occurring
"good" bacteria work to break them down. Since the bacteria cannot
completely decompose all of these solids, the layers continue to grow, slowly
filling up the tank. These solids will eventually have to be pumped out.
How
often should I pump? -TOP-
Many septic owners believe that if
they haven't had any problems with their systems, they don't need to pump out
their septic tanks. This is an unfortunate misconception. As your septic system
is used, solid materials settle to the bottom of the tank, forming a sludge
layer. Grease and lightweight materials float to the surface of the septic tank
as scum. Normally, properly designed tanks have enough space for up to 3 years'
safe accumulation of sludge. When the sludge level increases beyond this point,
sewage has less time to settle properly before leaving the tank. As the sludge
level increases, more solid wastes escape into the drainfield. If the
drainfield becomes so clogged that it cannot absorb liquid at the rate at which
it enters the septic tank, the plumbing will "back up" or unsanitary
wastewater will bubble to the surface. It is important to note that the
drainfield will not fail immediately when a full tank is not pumped. However,
continued neglect will result in costly system failure.
This chart will help you estimate, in years, how often to have your
septic tank pumped. It is based on the size of your tank and the number of
people in your home.
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Household size
|
|
Tank size
|
1
|
2
|
3
|
4
|
5
|
6
|
7
|
8
|
9
|
10
|
|
500
|
5.8
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2.6
|
1.5
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1.0
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0.7
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0.4
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0.3
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0.2
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0.1
|
--
|
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750
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9.1
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4.2
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2.6
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1.8
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1.3
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1.0
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0.7
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0.6
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0.4
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0.3
|
|
1000
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12.4
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5.9
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3.7
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2.6
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2.0
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1.5
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1.2
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1.0
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0.8
|
0.7
|
|
1250
|
15.6
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7.5
|
4.8
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3.4
|
2.6
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2.0
|
1.7
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1.4
|
1.2
|
1.0
|
|
1500
|
18.9
|
9.1
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5.9
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4.2
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3.3
|
2.6
|
2.1
|
1.8
|
1.5
|
1.3
|
|
1750
|
22.1
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10.7
|
6.9
|
5.0
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3.9
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3.1
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2.6
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2.2
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1.9
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1.6
|
|
2000
|
25.4
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12.4
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8.0
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5.9
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4.5
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3.7
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3.1
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2.6
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2.2
|
2.0
|
|
2250
|
28.6
|
14.0
|
9.1
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6.7
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5.2
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4.2
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3.5
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3.0
|
2.6
|
2.3
|
|
2500
|
31.9
|
15.6
|
10.2
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7.5
|
5.9
|
4.8
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4.0
|
4.0
|
3.0
|
2.6
|
|
Note: More frequent pumping needed
if garbage disposal is used.
Household Size (Number of People)
Tank Size (gallons)
|
Regardless of your individual pumping schedule, a septic system should be
inspected every 3 years. Your septic tank should be pumped at a minimum of
every 5 years. Click here for a list of pumpers.
How can I maintain my system? -TOP-
Septic systems can function very
well with minimal care. In fact, most septic tanks will only require an
inspection and pumping out by a professional every three years if they are used
properly. Most modern septic systems have a life span of nearly 25 years. Here
are some helpful hints you should follow to have a long-lived and trouble-free
operating septic system:
DO
THESE THINGS:
- Practice water conservation to reduce amount of waste
water.
- Reduce water from showers and baths. Install shower-head flow restrictors, take shorter
showers, bathe in shallower bath water.
- Fix leaking faucets or leaky toilet flush valve.
- Install low-flow toilets.
- Spread laundry throughout the week. Solids settle better in the septic tank when not given
large amounts of water in a single day.
- Consider a low-water use washing machine at replacement
time or before.
- Reduce the discharge of greases and oils.
- Reduce the solids that go to the septic tank by
limiting the use of the garbage disposal.
- Divert roof drainage from the drainfield area. Drainfields functions best
when the soil is not saturated.
- Protect your tank and drainfield from mechanical
damage. Your drainfield is not a road
or parking lot. Driving over the drainfield squeezes the soil together, which restricts the ability of water to move through the soil.
It can also cause cracking and shifting of pipes and components.
- Create a landscape that is suitable for your septic
system. Plant grass, not trees. Tree
roots seek out water and can break and clog pipes. Grasses increase the
oxygen exchange in the soil and help the evaporation process.
- Pump your tank on a regular basis. Every 3-5 years is recommended. Keep your receipts.
- Keep records.
- Give records or copies of them to the next owner if you
sell.
DON'T
DO THESE THINGS:
- Never put solvents, oil-based paints, or toxic waste
down the drain. Your local household hazardous
waste facility will take these items.
- Avoid any types of grease solvent drain cleaner. Your septic system is not designed to handle solvents
and you could contaminate the ground water by using them.
- Never use large quantities of acids, bases, or
oxidizers to "treat" or "clean" a septic tank.
- Don't use more than the recommended quantities of
"over the counter" drain cleaners.
- Don't use additives.
Most additives don't work and those that do tend to push solids from the
tank toward the drainfield.
- Don't build structures over your septic system or its
components.
- Don't pave over your system. Drainfields depend on air
entering through the soil, oxygen dissolved in rainwater, and
non-compacted soils.
- Don't allow cattle or horses, or other pasture animals
onto a drainfield area.
Soil compaction and mechanical damage can result.
- Don't repair without permits. Any short term saving could be offset by having the
wrong thing repaired or by legal entanglements.
- Do not flush:
- Coffee Grounds
- Tampons
- Kitty Litter
- Fats, greases, or oils
- Cigarette butts
- Wrapping paper
- Paper towels
- Newspaper
- Dental Floss
- Plastics
- Sanitary napkins
- Cotton swabs
What are the signs of a failing system? -TOP-
The most obvious signs of failures:
- Pooling of water or muddy soil around your septic tank
or drainfield.
- Odors of sewage or a "rotten egg" smell
around your septic tank or drainfield.
- Toilets, sinks and bathtubs backing up when you flush
or do laundry.
- Gurgling sounds when you flush or do laundry.
- Slow draining toilets, sinks and bathtubs.
If you have any of these signs or believe your system is failing, contact the
Health District immediately. You will be advised to fill out an application for
a repair and submit it
with the appropriate fee. Once the application is received, an inspector will
be out within two days to inspect your system and to advise you as to the
repair of that system. The homeowner or a professional installer can install the replacement septic
system if it is a non-engineered system.
A licensed installer is required to do the installation if the
replacement septic system must be engineered. Once the system has been repaired
and before it is backfilled, the inspector will do a final check of the system.
You will be sent a copy of the final inspection and the "as built,"
which shows the location of the repair.
About the BFHD 
Benton Franklin Health District