septic systems

Septic Systems

A Buyer’s & Seller’s Guide









First American Title

Insurance Company of Oregon

Created by Tod Hunt,

Regional Marketing Manager

Education Program Director

Jackson & Josephine Counties

First American Title Insurance Company of Oregon

Medford, Oregon

April 2006

Table of Contents



How Septic Systems Work pp 1-3

Septic Tank: Wastewater Separation p2

Drainfield: Wastewater Distribution p3



Locating System Components p4



Septic System Inspection & Pumping p 5-7

Inspection Items p5

Septic Tank Pumping pp 5-6

Septic Tank Inspection p7



Installing a New System pp 8-19

Permit Process pp 8-10

Site Evaluation pp 8-9

Soil Evaluation pp 9-10

Construction & Installation Considerations pp 11-13

Setback Requirements p 12

Drainfield Construction pp 13-14

Sand Filter Systems pp 15-18

Alternative Treatment Technology pp 18-19



Preventative Maintenance pp 24-28

Control Water Usage p 20

Drainfield Care pp 21-22

Pools, Spas, Runoff & Softener Issues pp 22-24

Stream Crossings p 24

System Alterations p 24



System Failure & Repair pp 25-27

Signs of Septic System Failure p 25

Causes for System Failure pp 25-7

System Repair p 27



Contractors pp 28-29



Site Development Plan Samples pp 30-32



Index p 33



Acknowledgments p 34

SEPTIC SYSTEMS

How Septic Systems Work

Owning a Private Sewer System

Do you know where the water goes when you empty a sink or flush a

toilet? If your home is in a city, the wastewater goes into a municipal

sewer system and to a sewage treatment plant. If your home is in a

rural area or a small community, chances are your wastewater goes

to your own private septic system. A septic system treats and

disposes of your sewage right in your own yard.



The septic system, if properly sited and when performing properly, safely treats and disposes of your

sewage without creating any danger to your health or to the environment. Normally you don't have

to worry about sewage in your yard. However, if the septic system is not functioning properly, there

can be health concerns. Therefore, it is a good idea to understand how a septic system works and

what you can do to make sure it continues to work properly.



How A Septic System Works

The purpose of on-site disposal systems is to provide for the treatment of household waste using

natural processes. A septic system with an absorption field is the most common method for treating

waste from a rural residence.

A typical septic system has three main components:



1. a plumbing collection system

2. a septic tank well

3. a drainfield

100 ft.



Plumbing: Wastewater Collection

All wastewater containing human wastes, nutrients, septic tank

dirt, and other contaminants must be collected and

delivered to the septic tank and drainfield for

diversion box

treatment and disposal. All water used in bathing,

toilets, laundry, and dishwashing must be treated by

the system. Drains allowing wastewater to enter the

system should be equipped with strainers and other

filtration devices to reduce the amount of food replacement

particles, hair, and lint entering the system. area soil absorption

system

Some older homes may have been plumbed to bypass

the septic tank with wash water but this has proven

unsuccessful and damaging to drainfields. Oregon's

rules require all wastewater to be treated. However, water from roof drains, basement drainage sump

pumps, hot tubs, and swimming pools should not be put into the septic system. These large volumes

of “clean water” will overload the system.



Original and remodeled plumbing systems must be correctly designed and installed to allow

trouble-free operation. Before remodeling, consider the impact of changes on the septic

system.









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SEPTIC SYSTEMS

How Septic Systems Work

Septic Tank: Wastewater Separation

The purpose of the septic tank is to separate the solids from the liquids in the wastewater stream

and to begin the process of breaking down contaminants. The tank is a buried, watertight container

typically constructed of concrete, steel, fiberglass or polyethylene and can range in size from about

1,000 to 1,500 gallons or more. To give you an idea of how large this is, consider that up to 50 gal-

lons of water fit in a standard bathtub and ordinary toilets use up to 3.5 gallons per flush. So, de-

pending on the size of your household, it doesn't take too long to fill the septic tank.



Two-chamber septic tank Most septic tanks have just one

interior chamber into which the

wastewater from your house enters;

though a 2-chamber system will

process influent more efficiently.

When the influent enters the first

chamber, its velocity slows so that

the heavier solids can settle out of

the water into the bottom of the

chamber, and lighter materials can

float to the surface. The

accumulation of settled solids at the

bottom of the tank is called sludge

and the lighter solids (greases, fats

and soaps) which form a mass on

Courtesy of Landmark Inspection Service the surface of the liquid in the

septic tank is called scum. In

between the sludge and the scum is liquid waste or wastewater.

Micro-organisms, like bacteria, and other natural processes act to decompose the waste materials in

the liquid waste. Incoming water should be held in the tank for at least 24 hours in order to improve

settling. Up to 50 percent of the solids will decompose into liquids and gases. Sludge and scum are

also digested and compacted into a smaller volume. This is the first step in the process of purifying

your household wastewater.

When the first chamber of the tank becomes filled, the liquid waste begins to fill the second chamber.

The chambers of the septic tank are designed to prevent the movement of sludge and scum to the

second chamber, allowing only the movement of liquid. Once the second chamber is filled, and more

influent enters the first chamber, an equal amount of the partly-treated liquid waste flows into the

second chamber, while an equal amount flows out of the second chamber into the leaching bed or

drainfield. The water flowing out into the leaching bed is called effluent. This is often referred to as

primary treatment.

Pathogens in the waste are NOT destroyed in the septic tank. Bacteria in the septic tank prepare the

wastewater for final treatment in the drainfield. The separate chambers, a T-shaped outlet, and often

screens in the septic tank prevent sludge and scum from leaving the tank and traveling into the

drainfield area. Biological and chemical additives are not needed to aid or accelerate settling or

decomposition. As a general rule, no solids other than human wastes and toilet paper should be

flushed.









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SEPTIC SYSTEMS

How Septic Systems Work

The Drainfield: Wastewater Distribution

The majority of the treatment of the wastewater occurs in the drainfield. A gridwork of perforated

pipes or clay tiles in the leaching bed area evenly distributes the effluent over the natural soil or

imported fill. Sometimes a distribution tank is used at the head of the pipes to more evenly distribute

the effluent to the pipes. Gravel supports and forms an envelope around the pipe, to protect it from

roots and burrowing animals. The perforations in the pipe allow the effluent to escape to the soil.

Uncompacted, unsaturated, undisturbed soil must surround the soil treatment system. This system,

typically referred to as secondary treatment, may be a series of trenches or a mound.



As the effluent filters through the soil, micro-

organisms in the soil digest and remove the

remaining impurities (such as suspended solids,

organic chemicals and viruses and/or bacteria).

There are millions of naturally-occurring beneficial

microscopic organisms in every tablespoon of soil

that kill disease-causing organisms in the sewage

and remove nutrients. These beneficial bacteria in

the soil need air to live. Therefore, a zone of

unsaturated soil must be present below the

drainfield for complete treatment.



A biomat, or thin layer of fine solids, dead

bacteria, and soil bacteria forms where the sewage

meets the soil. This biomat layer regulates how

fast liquid passes out of the trench or bed into the

soil so the soil beneath the trench remains

unsaturated. Once the wastewater is through the

biomat layer and three feet of unsaturated soil,

many harmful pathogens have been destroyed.

Eventually, the purified water reaches the

groundwater.

Courtesy of Landmark Inspection Service







If a soil has a high permeability or high water

table, the effluent can reach the groundwater

before it is fully treated. To avoid this, a shallow

trench or mound system design is sometimes

used. Both usually require a hydraulic pump to

ensure uniform distribution of effluent over a field.



As you can see, the operation of your septic

system is fairly automatic and can work quite well

by itself with very little maintenance required by

the homeowner. Note the key words though,

“little maintenance”, not “no maintenance”.









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SEPTIC SYSTEMS

Locating Your System Components

Finding Your System

Most people have never seen their septic system, and if the system is properly maintained, most may

never need to see it. A septic system is generally composed of two main parts: a watertight septic

tank and a network of perforated pipes, called a tile bed, leaching bed or drainfield. All these parts

are buried under your lawn so you may not even be aware of them. Yet, your septic system receives

all the wastewater from your house, including toilets, showers, sinks, dishwasher, washing machine,

etc. and purifies that water so it is safe to re-enter the ground water system.



Locating Your Septic Tank & Drainfield

Locating a tank, distribution box or

drainfield can be difficult. You might

plumbing vent see lids or manhole covers for your

septic tank. Older tanks are often hard

to find because there are no visible

parts.



leachfield/drainfield

To locate your drainfield, look for clues

septic tank such as shallow, parallel depressions,

which may mark the drainfield

trenches. It is unlikely that a drainfield

could have been installed among large

trees or in very rocky areas.

Effluent absorption

and purification

If all that fails, you can contact your

county health/sanitary department or

groundwater

the Department of Environmental

Quality to see if they have a copy of

the “as-built” drawing for the septic system for your home. The approved diagram would show

where your septic system components are located. The quality and detail of as-built diagrams varies

greatly. An older diagram, from before 1980, may be a very rough, simple sketch showing the layout

of your system. Even if they do have a drawing on file, it probably will not match exactly what is in

the ground, but it should be close.



A newer diagram will show the tank, drainfield, reserve area (to be protected until the time when a

replacement field is needed), and any other components of your system such as a pump chamber or

mound. The size of the tank and length of the drainfield lines may also be noted. If you can find out

who installed the system they should be able to tell you where

everything is.



Often a good contractor can tell where everything is just by the lay

of the land. And if they can’t spot it by eye, they have the tools to

find them. Some even have small radio transmitters that they can

flush down the drain and track as it goes through the system. Of

course, once you have the pro find everything, you can mark it

(there are small markers you can use to landmark the system) and

know where everything is.









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SEPTIC SYSTEMS

Septic System Inspections & Maintenance

Proper Maintenance of Your System

As a homeowner, you’re responsible for the maintenance of your septic

system. If properly designed, constructed and maintained, your septic

system should provide long-term, effective treatment of household

wastewater. A malfunctioning system is not only a health hazard to

your family and your neighbors, but will likely harm surface and ground

water resources, and cost you thousands of dollars to repair or replace.

Keep in mind that when you sell your home, your septic system must

be in good working order.



Septic System Inspection

You should have a typical system inspected at least every 3 years by a professional and your tank

pumped as recommended by the inspector (generally every 3 to 5 years). An inspection should

include:



• Locating the system • Measuring scum and sludge layers

• Uncovering access holes • Identifying any leaks

• Flushing the toilets • Inspecting mechanical components

• Checking for signs of back up • Pumping the tank if necessary





Pumping the Tank

Septic systems cannot dispose of all the material that enters the system. Solids that are not broken

down by bacteria begin to accumulate in the septic tank and eventually need to be removed. As the

septic system is used, sludge will build up in the bottom of the septic tank. The rate of the build-up

will depend on the size of your tank (bigger is better), the volume of wastewater entering the tank,

and the volume of solids in the wastewater stream.

If the sludge is allowed to accumulate to the height of the outlet pipe, it could flow into the next

chamber and then out into the tile bed. The pipes in the tile bed can become rapidly clogged by

sludge. When the pipe is all blocked and the wastewater can no longer leach into the soil, it will seep

to the surface of the ground, or worse yet, back up into your house. Not only can a clogged septic

system be hazardous to the environment and to your family's health, it also represents a very

expensive repair bill. Once the pipes become clogged, there is no quick fix; the entire system must

be dug up and replaced.



Properly designed tanks have enough capacity for three to

eight years use before needing service. The tank should be

checked each year starting with the third year to determine

how much sludge is there. It is important to understand that

septic tanks always appear full because both the inlet and the

outlet are at the top of the tank. The homeowner needs to

determine how much of the tank’s volume is being taken up by

solids, scum and sludge. When sludge and scum take up more

than 35 percent of the tank volume, these solids need to be

removed by pumping.









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SEPTIC SYSTEMS

Septic System Inspections & Maintenance

Pumping the Tank Suggested Pumping Frequency (Years)

Pumping should be more frequent for a smaller tank,

where more people are living in the house, and for

Tank Size Household Size (No. of People)

houses with garbage disposals. Not only will this

increase the capacity of the system by creating more (gal.) 1 2 3 4 5 6 7 8

room for the wastewater, but it will also prevent the

500 5.8 2.6 1.5 1.0 0.7 0.4 0.3 0.2

sludge from entering the tile bed area. Older homes

(built prior to 1974) may have a 500 or 750 gallon 750 9.1 4.2 2.6 1.8 1.3 1.0 0.7 0.6

tank. The smallest “approved” tank size since 1974

1000 12.4 5.9 3.7 2.6 2.0 1.5 1.2 1.0

is 1,000 gallons.

1250 15.6 7.5 4.8 3.4 2.6 2.0 1.7 1.4

It is recommended that you employ a septic tank 1500 18.9 9.1 5.9 4.2 3.3 2.6 2.1 1.8

pumper licensed by the Department of

Environmental Quality (DEQ) to pump and clean your 1750 22.1 10.7 6.9 5.0 3.9 3.1 2.6 2.2

tank. This is primarily for homeowner safety, since 2000 25.4 12.4 8.0 5.9 4.5 3.7 3.1 2.6

septic systems produce harmful fumes and can be

dangerous to clean for those not adequately 2250 28.6 14.0 9.1 6.7 5.2 4.2 3.5 3.0

prepared. Using qualified professionals also reduces 2500 31.9 15.6 10.2 7.5 5.9 4.8 4.0 4.0

the chance of improper monitoring or possible

damage to the system during pumping. It is worth

stressing again that it is much less expensive to maintain a system than to repair or replace it later.



It is a good idea to supervise the cleaning to ensure that it is done properly. The material pumped out

is known as septage. To get all of the material from the tank, the scum layer must be broken up and

the sludge layers stirred up into the liquid portion of the tank. This is usually done by pumping liquid

from the tank and reinjecting it into the bottom of the tank.



The best time to clean out the tank is summer to early fall. At these times, the ground will not be

frozen, allowing easier access to the tank, and the biological activity in the tank can re-establish itself

before it gets too cold (micro-organisms like it warm). In the spring, hydrostatic pressure from an

elevated water table—the result of melted snow or heavy rainfall— can sometimes create sufficient

pressure on the

underside of an empty

tank to push it up out

of the ground. This is

more of a concern

with lighter tanks

made of polyethylene,

fiberglass or steel.



Single

chamber

septic

tank

Diagram Courtesy of the EPA









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SEPTIC SYSTEMS

Septic System Inspections & Maintenance

Inspecting Your Septic Tank

All septic tanks should be checked on an annual basis to ensure they are working

properly. Baffles, specially designed pipes which allow the sewage into and out of

the tank, need to be checked to ensure they are not worn or damaged. The level

of sludge (the material that accumulates at the bottom of the tank) needs to be

measured to determine when the system should be pumped.



Before closing the tank, check the condition of the tees or baffles. If they are

missing or deteriorated, replace them with sanitary tees. Never enter a septic

tank. Any work to replace the baffles or repair the tank should be made from the outside. The septic

tank produces toxic gases which can kill a person in a matter of minutes. When working on a tank

from the outside, make sure the area is well ventilated and someone is standing by. Never go into a

septic tank to retrieve someone who was overcome by toxic gases or the lack of oxygen without a

self-contained breathing apparatus. In the event someone falls into a septic tank the best thing to do

is call for emergency service and put a fan at the top of the tank to blow in fresh air.

To facilitate cleaning and inspection, install a watertight riser and a gasketed cover from the central

service hole at least one inch above the surface before burying the tank. Do not bury the riser cover.



Before You Buy Property

Before you buy undeveloped property, ask if the property has been evaluated for a septic system. If

not, have DEQ or a local government contract agent evaluate it for a septic system before

purchase. When checking an existing septic system in a home you might want to buy, DEQ advises

that you hire a qualified inspector to check out the system. Here are the main things to investigate:



• Is the system legal? Was it installed with a permit?

• Is the system the proper size to accommodate the needs of your

family or business?

• How old is the system and has it been properly maintained?

• When was the septic tank last pumped?

• Have there been any problems in the past?

• Are all plumbing fixtures connected to the septic tank?

• How many people previously lived in the house?

• Are there signs of septic system failure such as soggy areas over the

septic tank or drainfield areas?



If you anticipate purchasing a property with intentions of making some changes in the use or size of

the home, you may need to secure an Authorization Notice. This inspection procedure is performed

when connecting or re-connecting to any existing septic system, when replacing one residence for

another, rebuilding or replacing any structure, even if destroyed by fire or other natural disaster, when

adding bedrooms or additional apartment facilities to an existing dwelling, connecting additional

dwellings, or when any proposed change in use results in an increase to either sewage flow or waste

strength. An Authorization Notice is usually not needed if you are adding more square footage,

bathrooms, or garages.









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SEPTIC SYSTEMS

Installing a Septic System

Installing a New System

The design and installation of a septic system is controlled by local

and state rules through the permit process. The permit takes into

consideration all specific site characteristics including the type of

soil, size of house, and wastewater-contributing fixtures and

appliances. The permitting process ensures that septic systems are

sited and constructed so that human health and the environment

are protected. In some counties DEQ administers the on-site

program, while in other counties the County government

administers the program as the agent for DEQ.

The system must be installed by licensed contractors and inspected by qualified officials to ensure

proper installation. Operation and maintenance of the system is the owner's responsibility.

Contact the local responsible agency (planning and zoning, environmental services, etc.) with

questions about local requirements. In Jackson County, contact Chuck Henke at 774-6931. In

Josephine County, contact Chuck Costanzo at 471-2850.



Permit Process

Getting a new septic system installed is a two step process. The first step is to apply for a site

evaluation. A septic system specialist will evaluate your property and identify the type of septic

system needed and the best location for it. The second step is to apply for a septic system

construction permit. Call your local DEQ office for application forms. There is a fee for a site

evaluation as well as for the permit.



Step 1: Site Evaluation

A. Site Evaluation Criteria

The suitability of a proposed site for a septic system is largely

determined by the type and depth of soil and the depth to

the water table. Other factors include the size of the prop-

erty, how steep the site is, location of the system relative to

streams, wells, cuts and fills, and whether sewer service is

available. There must also be enough area available for a full

system replacement in case the system fails.

B. Site Evaluation Process

1. The Site Evaluation Application form must be completely filled out, signed by the owner or

legally authorized representative, and submitted to the appropriate office along with the fee. A tax lot

map, a detailed drawing of the proposed development, and directions to the property must be

included. You must also provide at least 2 test pits at least 75 feet apart (more are necessary for

large systems) in the proposed drainfield area. The specific requirements for test pits are provided

with the Site Evaluation information packet.

2. After a completed application is received, an On-site Specialist will visit your property to perform

the Site Evaluation. Depending on weather, test pit placement and if additional test pits need to be

dug, more than one visit may be necessary. DEQ’s goal is to respond to completed Site Evaluation

applications within 3 weeks of receiving them however during the summer it may take up to 5 weeks.









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SEPTIC SYSTEMS

Installing a Septic System

B. Site Evaluation Process

You will receive a Site Evaluation Report that specifies the approved area, the type and size of the

septic system required and any special requirements. Should the site be rejected, you have 90 days

in which you may provide additional test pits for evaluation with no additional fees. The Site

Evaluation Report will also give you information such as applying for a site evaluation report review

and the opportunity to apply for a variance from any rule or standard.





Test Pits

When you apply for a permit to construct an onsite sewage

disposal system, a DEQ or County inspector will have to

visit the proposed construction site. A test pit allows the

inspector to test and examine the soil and soil layers and

will help determine if it is appropriate to proceed with

construction. This process is often referred to as a site

evaluation.

To provide for pit stabilization and safe access, standard

test pits for site evaluations must be prepared in the

following manner:

• The bottom of the pit shall be at least 2 feet wide and 4 feet long.

• The depth shall be at least 4.5 feet and shall not exceed 5 feet

In some instances, pits need only be excavated to the layer of hard rock or to the water table if that

layer is less than 5 feet.



Soil Evaluation

Soil is not only the foundation of your dwelling, but the foundation of wastewater treatment as well.

Every site has unique soil characteristics that are critical in determining the size and type of system

required. All soils are composed of sand, silt, clay, and some organic matter. The relative amount of

each determines the soil's texture. Coarse soils are composed primarily of sand. They may also

contain small amounts of fine gravel or rock. Intermediate soils are ones composed of a mixture of

sand and silt. Soils composed primarily of clays are called fine soils. Soils are further classified into

four basic structural groups. The four basic types of structure are: granular, platy, blocky, and

prismatic. The structure of a soil, as well as the texture, determines the permeability of the soil.



Underlying your site are several layers of soil composed of different

minerals and amounts of organic matter. Each of the four soil

structures has a specific location within these layers. These layers

make up what is called the soil profile. In ordinary, undisturbed soil,

the four types of structures are visible in this soil profile. Granular

structures predominate on the top, followed in succession by platy,

blocky, and finally prismatic structures. Below the topsoil and subsoil

is the substratum. It is in the substratum where a limiting layer would

exist. This layer of rock or very coarse sand limits the effectiveness of

the absorption field.









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SEPTIC SYSTEMS

Installing a Septic System

Soil Evaluation

There is much more to soil than just the inorganic particles that

contribute to it. Soil can be thought of as a miniature ecosystem.

The soil particles are surrounded by voids that can be filled with

air or water. Soils are classified as well drained, moderately well

drained, somewhat poorly drained, or poorly drained.



Unsaturated soil is necessary to provide oxygen to promote

chemical reactions or bacterial degradation. Therefore soils with

groundwater that is at least 2-3 feet below the trenches are

essential to promote proper treatment. The type of soil is also

important. Soils such as sand allow the water to percolate

downward. This will enhance treatment and prevent water from flow upward to the surface. Clay soils

are less ideal, because the water does not flow as readily through it, and areas with shallow bedrock,

do not allow the use of absorption fields at all.





Step 2. The Permit

A. Permit Criteria

A Construction-Installation Permit is usually what is needed to install a septic system for a

single-family dwelling or a system that has a projected sewage flow less than 2,500 gallons per day.

This permit is valid for 1 year. For an additional fee it may be renewed or reinstated if it takes longer

to complete construction and installation. If you have questions about permits for larger or more

complex systems, contact DEQ at (503) 229-6504 or toll free in Oregon at (800) 452-4011 or the

local Grants Pass DEQ at 541-471-2850.

You must have a favorable Site Evaluation Report in order to apply for a Construction-Installation

permit. A permit application packet can be obtained from the onsite agent for your county.

B. Permit Process

1. To prevent a delay, fully complete the application, including the owner’s or legally authorized

representative’s signature, and submit it along with the required fees. At a minimum, the

following documents must be attached:



A. A copy of the Site Evaluation Report.



B. A Land Use Compatibility Statement signed by your county’s land use agency.



C. A vicinity/locator map.



D. A detailed Site Development Plan and directions to the

property.



E. Detailed plans and specifications for the installation of

the system.



For Construction-Installation permitted systems, the plans must

be drawn by the property owner or a DEQ-licensed installer.









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SEPTIC SYSTEMS

Installing a Septic System

Construction, Installation and Inspection

2. A Construction-Installation Permit will be issued within 20 days of

receiving a completed application. Once you have the permit in

hand, you may proceed with the installation of the septic system

prescribed in the permit. Any changes must receive approval from

the on-site agent for your county.



Note: A septic system must be installed and constructed by the

owner or a DEQ-licensed installer using DEQ-approved materials and

equipment that meet minimum standards. All equipment must be installed and operated according to

the manufacturer’s specifications. If you have questions about installers or approved materials and

equipment contact DEQ at 503-229-6504 or toll free in Oregon at 800-452-4011



3. A “pre-cover” inspection (before it is covered with soil) of the installation is required unless

waived by the on-site agent for your county. Some complex systems, such as sand filter systems,

require inspections at various stages of construction—these requirements are specified in the permit.



To initiate the pre-cover inspection the installer must complete the As-Built Drawing and Materials List

form (included in the permit packet) and submit it to your county’s on-site agent. This form must be

signed by the installer certifying that it was installed according to DEQ specifications. Within seven (7)

days of receipt of this completed form, the on-site agent for your county will either waive or conduct

the inspection.



After completion of a satisfactory inspection, you may cover the

installation. You will be sent a Certificate of Satisfactory

Completion (CSC) in the mail. Upon receipt of the CSC, you may

begin using the septic system.



The design, size, and location of a septic system are dependent on the

characteristics of the site. These include topography, soil

conditions, geology, and drainage. As the properties are identified,

decisions regarding the design and construction can be made.

Critical to the location of the absorption field is the topography of the site. A topographic profile

shows the basic types of landforms. A contour map shows varying elevations in which each line

represents a set elevation change.



When locating the absorption field on the site, areas where

water naturally converges should be avoided. Depressional

areas and floodplains must be avoided since these areas

may become saturated and be unable to adequately treat

the effluent flow. A "useable area" of soil absorption should

be located in an area of diverging flow. This area can be

triangular, or trapezoidal in shape, but is most commonly

rectangular. The larger the available area, the easier the

system layout will be.









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SEPTIC SYSTEMS

Installing a Septic System

Constructing a Drainfield

The absorption trenches should be placed perpendicular to the

slope. Another way of saying this is that the trenches will be parallel

to the contour lines. The exact slope of the site must be determined.

Knowing the elevation change from the house to the absorption field

is critical. If the field is located uphill from the house, hydraulic

pumps will need to be included in the design. A complete layout of

your site, including dimensions and locations of roads, buildings,

neighboring residences, wells and drainage-ways, is needed before a

septic system is designed.



Setback Requirements

Oregon code requires that the septic tank of a septic system must be located at least:

5 feet from any building

50 feet from any well or year-round body of water

5 feet from the property line

25 feet upgrade or 50 feet downgrade from an irrigation ditch

Oregon code requires that the drain field of a septic system must be located at least:

10 feet from any building.

100 feet from any well or year-round body of water

10 feet from the property line

25 feet upgrade or 50 feet downgrade from an irrigation ditch

10 feet from any utility lines



Other Pre-Construction Site Considerations

After accounting for all of these separation distances, you can

determine the useable area remaining. Don't forget to allow for any

possible future construction. Don't place your drain field in a location

that would be ideal for a pool, deck, basketball court, or some other

future addition. Before any construction is allowed to proceed,

precautions should be taken to ensure that the absorption site is

protected from the compaction that might occur from construction

traffic. Be sure to stake off and fence this area as well as an

additional 90 feet down-slope. Under no circumstances should

construction traffic be in this area. Nor should it be used for storage

of construction materials. Even the backhoe used to construct the trenches can cause compaction if

soil conditions are not ideal for construction. Dig from the upslope side!



Before allowing construction to proceed, be sure that the soil is relatively dry. If the soil is too wet,

construction will damage soil structure. This could cause the septic system to fail or function poorly. A

good test for determining if the soil is too wet to excavate is to take a small amount and try to form a

ribbon of soils in your hand. If the soil holds the ribbon when you open your hand, it is too wet to

allow construction to proceed. If the soil crumbles and will not stay formed when you open your hand,

then it is probably safe to allow construction to begin.









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SEPTIC SYSTEMS

Installing a Septic System

Excavate in the Dry Months

It is best to plan the construction of your septic system to take

place from the middle to late summer months. This is when the

ground will generally be the driest and the water table be at its

lowest. In the autumn the water table usually rises due to the

fall rains. It may be difficult to find a time during the fall when

the soil will be dry enough to work and the water table not so

high that it floods the trench construction. During the winter,

the water table may fall some from its fall level, but the soil is often too wet or even frozen to work.

In the spring, the water table is often very high as a result of spring rains and runoff from thawing

snow and ice. Do not plan construction for the spring unless an early and dry summer is expected.





The Drainfield: Soil Treatment System

Common terms for the soil treatment system are: drainfield, leachfield, subsurface disposal field, and

soil absorption field. The soil treatment unit is where the final treatment and disposal of the septic

tank effluent takes place. A properly sited, designed and installed soil treatment system will destroy

most disease-causing pathogens and filter out the fine solids contained in the septic tank effluent.



Leaching fields generally consist of a network of perforated pipes laid in a gravel-lined trench into

which effluent is discharged from the septic tank. The purpose of the absorption field is to utilize the

unsaturated portion of the soil to provide aerobic (with oxygen) treatment of the effluent through the

chemical, physical and biological

properties of the soil.



The soil absorption field provides

secondary and final treatment of the

effluent discharged directly from a

septic tank or tertiary and final

treatment of effluent discharged

from a pretreatment unit such as a

sand filter.



Drainfield Installations

Site conditions and local

requirements determine the soil

treatment system for each site.



If there is four feet of separation

from the bottom of the disposal to

the saturated soil, a gravity flow,

standard system may be

approved. A standard system is the

least expensive sewage treatment

system.

Courtesy of Landmark Inspection Service









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SEPTIC SYSTEMS

Installing a Septic System

Conventional Trench System

Drainfield trenches effectively treat liquid flowing from the septic tank.

They are the most economical to install and are preferred when

possible. A drainfield trench is a level excavation 18 to 36 inches wide.

The depth of a trench can vary from one foot to a maximum of three

feet and up to 100 feet long. The trench contains a perforated pipe in a

bed of 3/4-inch to 2-inch diameter rock covered by natural or synthetic

permeable fibers. Some soil treatment systems use large plastic tubing

or some other chamber wrapped with fabric in the trench in place of

rock. A 6 to 12-inch deep layer of topsoil covers the trench.

Parallel trenches are used to ensure adequate treatment and are

generally 10 feet apart from center to center. A typical bed is about

fifteen feet in width. Sewage flows through the holes in the distribution

Courtesy of Landmark Inspection Service

pipe, to the rock (or tube), through the biomat, and into the soil.

Bacteria and fine sewage solids are removed or destroyed in this process.



The trench system may be laid out in one of

many configurations—including serial and equal

distribution methods to allow for the necessary

square feet of surface. The ground surface level

of the soil treatment area should always be level

or slightly raised above the surrounding ground

to avoid excess rainfall flooding the system.



Proper design and installation of the field is

critical to ensuring proper and complete

treatment. Professional installers licensed by the

state must be used to design the entire septic

system. The soils are examined by a local DEQ

or county agent to ensure that the soils are

appropriate for use of the field system. Proper

design requires that an additional reserve or

repair area be set aside in case the current

system fails. Some counties may also require

the installation of the additional field.



Distribution System

Each site has a unique shape and slope. The soil

type, percolation rate, water volume to be

treated, and other factors determine how large

an area is needed to properly treat sewage. To

provide the necessary area, the design may be

a series of many pipes, or "stepped" down a

slope. The distribution of effluent into the soil

treatment system is accomplished using drop

boxes and diversion or distribution boxes.

Diagram courtesy of Oregon Department of Environmental Quality









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SEPTIC SYSTEMS

Installing a Septic System

Sand Filter Systems

Septic tanks with soil absorption systems are the most

commonly used wastewater treatment system in rural and

suburban areas. Unfortunately, in many rural areas of Oregon,

soil and site conditions make it impossible to use a conventional

subsurface soil absorption system for wastewater treatment

and disposal. On these problem sites, sand filter systems may

be an alternative.



A single-pass sand filter system pre-treats septic tank Raised sand filter bed

effluent by filtering it through sand before sending it to a soil

treatment system. Various sand filter types and designs have

been extensively tested and used in the United States. Other

wastewater treatment filters use peat, pea gravel, crushed

glass, or other experimental media, but sand is the best

understood and the most predictable.



Treatment mechanisms in a sand filter include physical filtering

of solids, ion exchange (alteration of compounds by binding and

releasing their components), and decomposition of organic

waste by soil-dwelling bacteria.

Sand filter system construction

A properly operating sand filter should produce high-quality

effluent with less than 20 mg/liter BOD (biological oxygen Septic

demand, a measure of organic material), less than 20 mg/liter tank pump

tank

TSS (total suspended solids), and less than 200 cfu/100 ml Sand

filter pump

fecal coliform bacteria, an indicator of viruses and pathogens. tank

Distribution

system





Since wastewater leaves a sand filter system as high-quality

effluent, the soil in the trench or mound soil treatment system

may be better able to accept it, and the system should last

longer.



Because sand filters produce cleaner wastewater, they are

Sand filter enhanced septic system

useful for sites that are small; and for sites that are

environmentally sensitive like those near lakes, in shallow

bedrock areas, aquifer recharge areas, and wellhead protection

areas. Pretreatment may allow a reduction in the separation

required between the soil treatment system and the limiting soil

layer.



Sand filter systems may also be successfully retrofitted into

conventional trench drainfields that have failed because of

excessive organic loading from lack of maintenance.









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SEPTIC SYSTEMS

Installing a Septic System

How Sand Filter Systems Work

Sewage flows from the house into one or several septic tanks, depending upon the size of the house

and local requirements. Effluent from the septic tank(s) flows into a pump or lift tank. A pump

introduces the effluent at the top of the sand filter, using pressure distribution to apply the

wastewater evenly to the filter surface to maximize treatment. A timer can be used to dose the entire

surface of the filter intermittently with wastewater. This draws oxygen from the atmosphere through

the sand medium and its attached microbial community.



The effluent is treated by physical, chemical, and biological processes. Suspended solids are removed

by mechanical straining due to enhanced contact and sedimentation. Treatment occurs through the

bacteria that colonize in the sand grains. Microorganisms use the organic matter and nutrients in the

effluent for growth and reproduction.



Intermittent Sand Filter

With an Intermittent Sand Filter, effluent is applied in intermittent doses to a bed of sand or other

suitable media. The ISF system is a “one-pass” system, meaning that the effluent percolates through

the sand media just once before it is passed onto the drainfield for the tertiary and final treatment.

The dosage, delivered at either a timed interval or on demand, is expressed at a maximum of 1.25

gallons / square foot or 45 gallons per dose. Timed intervals prevent system overload, but require

adequate septic tank storage to hold the high-volume effluent created during peak hours of use.



Recirculating Gravel Filter

With a Recirculating Gravel Filter, partially clarified effluent from the septic tank flows into a

recirculation tank. In the recirculation tank, raw effluent from the septic tank and the sand filter

filtrate are mixed and pumped back to the sand filter bed. Through this process 80% of the effluent

in the tank is reprocessed, while the remaining 20% of the effluent is passed on to the drainfield for

final treatment in the soil. These RGF systems are typically used for commercial or industrial

applications, like restaurants which have a much higher oil and grease content in the wastewater.

Dosing rates for RSF systems can distribute effluent at a maximum rate of 5 gallons / square foot or

180 gallons per dose.



To determine the design size of the filter, the volume of wastewater flow from the residence is

divided by the loading rate. The length to width ratio is not as critical as providing a system that

distributes wastewater evenly across the filter surface at regular intervals.





Recirculating gravel, 12”



from Gravel Filter sand, 24”



dwelling gravel, min. 12”

with slope of

base = 1” per 8’

Septic tank

Recirculation line

Recirculating tank return to pump





Pump To drainfield









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SEPTIC SYSTEMS

Installing a Septic System

Site Placement

Site flexibility is probably the biggest advantage of a sand filter

system. Because the filter is usually watertight and uses media for

treatment, the soil where it is constructed is not as important as the

ability of the media in the filter to transfer oxygen. Without enough

oxygen, bacterial action will be compromised.



The system should be constructed to keep surface water from

entering the filter. Outflow drainage from the filter is provided by a

four-inch pipe surrounded by pea rock. Depth of outflow should be

one foot to 18 inches below the bottom of the sand. The effluent

must drain freely out of the sand, since filter saturation reduces High-rate sand filter

treatment effectiveness. A Bottomless Sand Filter, where

wastewater is discharged directly to the soil beneath the sand filter

may sometimes be allowed.



Final Disposal of Wastewater

Effluent discharged from this system will be very clean, but must

still be applied to the soil for final treatment. Effluent leaving the

sand filter is sent to a soil treatment system, usually a drainfield.

The effluent is so "clean," a biomat layer does not form the way it

does in soil treatment systems receiving effluent from septic tanks.



A pressure distribution network may be used to apply effluent

evenly throughout the system. Options for the soil treatment system Low-rate sand filter

include trenches, and drip distribution.



Operation and Maintenance

All the routine operation and maintenance practices suggested for any onsite treatment system apply

to sand filters. Sand filters require more maintenance than a conventional septic-tank-drainfield

system, however. A maintenance contract therefore is strongly recommended.



Maintenance includes inspecting all components

and cleaning and repairing when needed. Visual

inspection of the effluent is required and often a

laboratory analysis is necessary. A flow meter

should be installed and periodically checked to

ensure the right amount of effluent is being

applied to the system.



Daily running costs for a sand filter are based on

the operation of a small submersible pump, and

average less than a dollar per month for an

individual home. Overall operational costs of

$200-$500 per year includes cleaning tanks,

repairs, maintenance, and electricity.









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SEPTIC SYSTEMS

Installing a Septic System

Sand Filter System Costs

Sand filter systems are expensive. The high price associated with a sand

filter system is due to the materials and system components required to

construct the system and the amount of time it takes to build the system.

A typical standard system takes approximately two (2) to three (3) days

to construct while the alternative sand filter system can take seven (7) to

fourteen (14) days to construct. The time it takes to construct a sand filter

system increases the costs associated with equipment time necessary to

build the system and equipment operator expenses.



A sand filter can operate for a considerable number of years if regular maintenance of the sand filter

occurs. There are sand filters that have been operating in excess of twenty years with no operational

failures. Sand filters do, however, require regular maintenance to remain operational for extended

periods of time. Regular maintenance is the periodic but regular pumping of the dosing septic tank by

a licensed septic tank pumper, and a yearly inspection of the effluent pump components to determine

if they are operating satisfactorily. All operational problems associated with a sand filter system must

be corrected immediately to maintain the satisfactory operation of the sand filter system.



Alternative Treatment Technology

Orenco AdvanTex

Orenco Systems provides complete wastewater treatment and

disposal systems. Products range from effluent filters that can be

retrofitted to an existing septic tank/soil absorption system to

complete turnkey systems for new construction. These systems

provide a higher level of treatment (organic content and solids

removal) than most conventional designs, and can be modified to

meet particular treatment objectives. They can provide nutrient

removal, disinfection, and enhanced organic and solids treatment.

The systems are very maintainable, and are available in a number

of configurations to meet a wide variety of site constraints.



Treatment methods are based on fixed film biological growth and physical straining, and units include

AdvanTex™ Textile Filters (AX & RX), Recirculating Sand Filters (RSF), and Intermittent Sand Filters

(ISF). All three are designed to support a diverse bacterial population on the surfaces of the media.

The bacteria use the nutrients and carbon sources in the wastewater for food and energy. The pore

structure of the treatment bed media enhances solids removal by physically filtering out

contaminants. Ultraviolet Disinfection Units for disinfecting the treated effluent before final discharge

are also available.



Orenco's AdvanTex™ Treatment Systems are an innovative technology for onsite treatment of

wastewater. The heart of the system is the AdvanTex™ Filter, a sturdy, watertight fiberglass basin

filled with an engineered textile material. This lightweight, highly absorbent textile material treats a

tremendous amount of wastewater in a small space. For example, the AX10 model has more than

20,000 square feet of surface area for biological breakdown of wastewater components, yet has a

footprint of only 10 square feet.









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SEPTIC SYSTEMS

Installing a Septic System

Orenco AdvanTex

AdvanTex™-AX systems are loaded up to 45 gallons per ft2

per day, RX systems are loaded at 20 gallons per ft2 per day.

ISF's are typically loaded between 1.25 and 2.0 gallons per

ft2 per day. RSF's are loaded at up to 5 gallons per ft2 per

day.



These systems provide a very high level of treatment with a

relatively low capital expense and very low operating costs.

In addition, the long-term performance of the systems is

enhanced thanks to excellent access to all system

components and overall ease of maintenance.



A typical three-bedroom home with flows up to 450 gallons

per day, using screened septic tank effluent, would require 10 square feet for an AdvanTex™-AX

system, or 90 square feet for an RSF or 360 square feet for an ISF. Disposal field requirements

depend on state allowances for secondary or tertiary-level treated effluent.



These systems require a primary settling basin, typically a septic tank, space for the treatment unit,

and an available disposal area. The AdvanTex™ systems commonly are placed right on top of the

septic tank between the inlet and outlet access risers. The sand filter treatment units are not more

than 4 feet deep so, as long as a septic tank can be installed, there will be sufficient depth for the

entire system. The effluent from these systems is considered secondary or tertiary. It is typically

disposed of in a conventional subsurface soil system sized at 25 to 50%. An easily installed and

cost-effective pressurized gravel-less chamber system is also available. If required, effluent can be

disinfected for reuse or delivered to a receiving body of water, wherever local regulations allow this

method of disposal.



As with all wastewater treatment and disposal systems, periodic inspection of systems is

recommended. For a typical three-bedroom system, an annual inspection and maintenance for the

system is performed in less than one hour. OSI systems are designed with alarms and safeguards

in order to alert the user of any problems that can develop with alarms, pump and float failures,

and Biotube effluent filter clogging. Homeowners or system installers can easily remedy all of these

potential problems. A new line of 'smart' control panels can diagnose a problem and make

recommendations for what should be done to rectify the problem; troubleshoot

the system automatically and make self-adjustments, and if needed, based on

trend data; notify the operator of needed maintenance.



Costs can vary widely depending on chosen system components, level of

product supply and site constraints. A typical three-bedroom application would

cost between $7,000.00 and $15,000.00. Costs will obviously vary due to

locally available products, site constraints, and labor rates. Construction

generally requires a backhoe operator and crew of 2, plus an electrician. A

typical installation will takes one to four days from start to finish.









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SEPTIC SYSTEMS

Preventative Maintenance

What you put into your septic system will have a direct effect on whether or not you have a healthy,

long-lasting and trouble-free system. Your septic system is not a dispose-all.



Control Water Usage

Average indoor water use in the typical single-family home is almost 70 gallons per person per day.

Leaky toilets can waste as much as 200 gallons per day. Toilet use accounts for 25 to 30 percent of

household water use alone.



Every time you put water into the septic tank, that same amount of water moves

into the leaching bed. So, the faster you put the water into the tank, the faster it

moves into the leaching bed. However, it takes time for the solids to settle out of

the liquid waste and for the micro-organisms to digest the solids. The longer the

retention time, (the time that the wastewater is allowed to remain in the septic

tank), the more separation and settling that occurs. If you cause the water to move

too quickly through the system, less “processing” and settling occurs before the

water reaches the leaching bed and the effluent may be discharged to the soil while

still containing pollutants in unacceptable concentrations. Insufficient settling can

lead to prematurely clogged drainfields and expensive repairs.

Therefore, limiting the use of water in the home will go far in prolonging the life of the system.

• Use water-saving shower heads and faucet aerators.

• Install low-flow toilets.

• Make sure sump pumps, roof drains, water softener backwash are not connected to the sewage

system.

• Use front load washers and space out the time between washings.

• Run the dishwasher or washing machine only when they are full.

• Fix leaky faucets and toilets. A tap leaking just one drop per second wastes more than 2,500

gallons of water per year. A silently leaking toilet can waste up to 20 times that amount.



Watch Your Drains

Controlling what goes into the water that enters the system is just as important as

reducing the amount of water that flows into the system.

• Don’t wash or flush medicines or hazardous chemicals like paint, paint thinner

and bleach into the system. They kill the bacteria needed to decompose

wastes in the septic tank and drain field and have the potential to

contaminate groundwater.

• Refrain from putting any plastic, cloth, or unnecessary paper products into

the sewage system.

• Avoid using garbage disposals as they accelerate the accumulation of solids

in the holding tank. Especially avoid putting any grease or oil in the

disposal or drain. These can clog pipes and drainfield soil and may likely

damage your system.

• Don’t flush material that will not easily decompose, such as hair, diapers,

cigarette butts, matches, or feminine hygiene products.









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SEPTIC SYSTEMS

Preventative Maintenance

Care for Your Drainfield

The drainage field is an often overlooked aspect of the septic system,

yet it is more important than the tank for the proper operation of the

entire system. The area over the leaching bed should have a good

cover of grass. Good ventilation and adequate sunlight should also

be maintained to promote evaporation. This means that you should

avoid constructing parking areas, patios, tennis courts or decks in the

area of, or over, the leaching bed. The weight of such constructions

could crush the pipe in the leaching bed preventing it from working

properly. Covering the leaching bed could also prevent oxygen from getting into the soil. The

micro-organisms responsible for digesting the waste material need oxygen to survive and function.



Homeowners can take several measures to ensure their drain field is properly maintained.

• Never park vehicles or place other large objects on the drain

field, as this will compact the soil and reduce its ability to

treat wastewater. It also may damage the network of

drain pipes within the field, causing them to need to be

replaced.

• Effluent from sump pumps and roof drains should not be

discharged in the vicinity of the drainfield, as this could

keep the soil too wet, reducing its capacity to absorb the

waste water and causing it to puddle on the surface,

creating an environmental and health hazard.

• Check for depressions in the drain field where surface water can collect. The drain field should be

level with the surrounding soil to discourage puddling. If the drain field is on a sloping site,

surface water diversion may need to be considered.

• Keep your septic tank cover accessible for inspections and pumpings.

• Cover the drain field with a grass cover to prevent erosion and remove excess

water.

• Avoid planting water-loving shrubs (especially willows and poplars) with deep

root systems or trees near the drainfield, as roots could damage the pipes,

or they could change moisture levels within the soil causing it to be less

effective.

• Don’t water the grass over the leaching bed. The additional water may

interfere with the ability of the soil to absorb liquids and break down waste.

• Don’t make or allow repairs to your septic system without obtaining the

required permit. Use professionally licensed septic contractors when needed.



Use of Additives

The use of additives to help maintain the system is not recommended. They will not extend the

amount of time required between pumping, and, although they may not harm the septic tank, they

could contaminate the soil. The most effective method of breaking down the solid matter in the

sewage is allowing the naturally present bacteria to digest it.









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SEPTIC SYSTEMS

Preventative Maintenance

Keep Maintenance Records

It is helpful to draw a diagram of the septic

system which shows the location of the house, the

septic tank and its manholes, and the drain field.

This diagram will make it easier for a qualified

maintenance worker to check and maintain the

system. Sketch a diagram showing the location of

your septic tank and drain field in relation to your

house. Measure exact distances from at least two

reference points (such as the corner of the house

and a tree) if possible. This need only be a sketch,

although the more accurate the drawing, the more helpful it will be in the future, so include

measurements of distance wherever possible. There is usually a good system diagram at your local

Health, Planning or DEQ office.



Keep a record of maintenance on your system. It is suggested that you include who maintained the

system, what was done, the date of the work, and the current status of the system. Looking after

your septic system is easy, and if you follow all the suggestions for maintaining your septic system

and prolonging its life, it should last twenty years or longer - and that's based on year-round use.

Unfortunately, just like many building components, eventually all septic systems will need to be

replaced.



Special Considerations

Swimming Pools & Hot Tubs

Water from swimming pools and hot tubs often contain high levels of chlorine. Discharging chlorinated

pool or spa water into steams, irrigation canals or ponds is harmful to fish and other aquatic life.

Besides being harmful to the beneficial bacteria in your septic tank and drain field, the volume of

outflow, if sent through the septic tank, will flush out much of the pretreated waste in the tank,

saturate your drainfield and likely clog the distribution pipes in the leaching beds.



When discharge to a sanitary sewer is not possible, the water from your pool or spa may be

disposed of on the ground or irrigated on your property under the following circumstances:

• Prior to disposing or irrigating the water, shut off the chlorination system, if you have one, or stop

adding chlorine.

• Hold the water in the pool or hot tub for at least one week to reduce the chlorine level.

• Discharge or irrigate the water in an area where the water will

not flow into a stream or storm sewer, flow off your

property, or create a nuisance condition (such as creation

of odors, and fly and mosquito breeding conditions).

Nuisance conditions occur when water sits undisturbed for

a prolonged period.

Water from back-flushing pool filters should not be discharged to a

stream, ditch or storm sewer, but discharged to a sanitary sewer,

on-site septic tank and drainfield system, or a seepage pit.









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SEPTIC SYSTEMS

Preventative Maintenance

Divert Runoff from the Septic Area

The soil in the sewage disposal area is expected to absorb the effluent from the septic tank. If the soil

is wet or saturated with rain water runoff from downspouts, driveways or patios, it may not be able to

handle the tank effluent. This may result in failure and the tank effluent may back up onto the ground

surface. Every effort should be made to avoid discharging storm water runoff onto the sewage

disposal system area of your property.



Water Softener Backwash

Parts of the U.S. have what is commonly referred to as "hard water," and

people who live in these areas battle the problems that hard water creates.

The most common defense against hard water, which is a nuisance but not a

health hazard, is to install a home water softener.

Water softening involves exchanging calcium and magnesium minerals

present in the water – which cause the hardness – with sodium. As the water

softener processes gallon after gallon of hard water on a daily basis, the

treatment capability of the softener becomes depleted and must be recharged

or regenerated.

Regenerating the unit uses a large quantity of sodium-rich water, called brine,

that must be disposed of. In homes with onsite septic systems, this brine flows

into the septic tank and eventually makes its way to the system's drainfield.



Sodium’s Role in System Failure

People using home water softeners often wonder whether these units might cause problems for their

onsite septic systems. Some common questions consumers ask are:

1. Do water softeners hurt the bacteria that work in a septic tank?

2. Does the concentrated salt water used in regeneration decrease the drainfield's ability to absorb

wastewater?

Unfortunately, experts don't all agree on the answers to these questions.

The equivalent of 56 pounds of table salt are discharged into the drainfield soils each year from a

household of 3-4 users. Within 4-10 years, sodium discharge begins to effect the ability of disposal

soils to treat and absorb domestic waste water. The amounts of sodium used, the precise nature of

local soils, and the volume of drainage area in the system vary, of course.

The high sodium content of household products for laundry,

kitchen, bath and cleaning are a primary source of soil failures.

Addition of water softener wastes or sodium content in the local

water supply also contribute to the problem.

Agricultural soil and wastewater scientists have long recognized

that in time, sodium in irrigation waters will cause finer soil

particles to bond together into impermeable layers. In

agriculture, this chemical change causes physical or structural

changes in the soil which ultimately leads to loss of biological

uptake of plant nutrients.









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SEPTIC SYSTEMS

Special Considerations

In the septic system drainfield, problems begin when a thin impermeable layer of bonded fine

particulate develops directly under the leachlines or on the trench floor or walls. This layer grows in

density over time and soon a "waterproof" barrier prevents access to the absorptive active soil

surfaces needed for maximum organism contact and cleanup of wastes.



Stream Crossings

If your building location is on one side of a stream and your approved

drainfield area is on the other, you’ll need to cross the stream with an

effluent sewer pipe to send wastewater from your septic tank to the

drainfield. A permit from DEQ is required to install any part of the system.

Oregon’s Removal-Fill Law requires people who plan to remove or fill

material in waters of the state to obtain a permit from the

Department of State Lands (DSL) including:

• Projects requiring the removal or fill of 50 or more cubic yards of material

in waters of the state,

•The removal or fill of any material in a stream designated as essential

salmon habitat, regardless of the number of cubic yards affected,

•The removal or fill of any material from the bed or banks of scenic

waterways regardless of the number of cubic yards affected.



If in doubt, check out the DSL website at http://statelands.dsl.state.or.us/.





Septic System Alterations

If you have the need to make changes to your existing septic system that

require the change in location of the tank or effluent sewer, you would need

to secure a Minor Alteration Permit. If your alterations to your system

include the expansion of or the relocation of an existing system that involves

your drainfield, you would be required to acquire a Major Alteration Permit.

To complete the process you would need to:

1. Complete an application form and pay a fee.

2. Provide a vicinity / locator map on an 8 1/2” x 11” sheet of white paper showing how to get to

your property.

3. Submit a detailed site plan to scale delineating the location of all existing development—structures

and improvements—with the actual distances between structures indicated.

4. Submit a tax lot map—which you can acquire from the local county assessor’s office.

5. Submit a land use compatibility statement signed by your county and/or city planning department.

6. Fill out the existing septic system description form and submit.

7. Locate the existing system for the inspector.

8. Major Alterations may require that at least one test hole be dug in the proposed area of the new

drainfield. Check with the inspector to determine if this is required prior to permit application.

9. Submit a detailed construction/installation plan after the site inspection is complete.

10. Include your name, township, range, section and tax lot or account number on all maps and

drawings submitted.









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SEPTIC SYSTEMS

Septic System Failure

Signs of Septic System Failure

Some of the warning signs that your septic system may be failing include

the following:



• The grass over the leaching bed may be much greener and lush than

other areas of the lawn.

• The ground around the septic tank or over the leaching bed may be

soggy or spongy to walk on.

• Toilets, showers and sinks may back up or may take longer than usual

to drain.

• Occasional sewage odors may become noticeable, particularly after a

rainfall.

• Gray or black liquids may be surfacing in your yard or backing up through fixtures into the house.

• You may notice significant algae growth in or around nearby lakes or water bodies.

• High levels of nitrates, bacteria or other contaminants may be found in nearby well water.

• Pools of water or soggy spots, foul odors, and/or dark gray or black soils in the area of your

drainfield.

• Water that surfaces over the drainfield during heavy rain or when doing laundry.

• Sewage backs up into the lowest drains in the house.

• Gurgling of drains, slow drainage (check for clogs first).





Causes for Septic System Failure

Septic system failure may be chemical, biological or physical.

These three conditions often occur in sequence. For instance,

when toxic chemicals are dumped into your drains, they can kill

the beneficial bacteria in your septic tank, which could lead to

insufficient digestion of the solids in the tank and force solids

into your leach field system where it congests and destroys the

soils ability to breakdown and absorb effluent.







Saving Money

A key reason to maintain your septic system is to save money! Failing septic

systems are expensive to repair or replace, and poor maintenance is often the

reason. Having your septic system inspected regularly is a bargain when you

consider the cost of replacing the entire system. An unstable septic system or one

in disrepair will lower your property value and could pose a legal liability.









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SEPTIC SYSTEMS

Septic System Failure

Causes of Septic System Failures

Chemical: You should avoid putting anything into the septic system that is toxic,

poisonous, flammable/combustible, explosive/reactive, corrosive or caustic.

Anything that doesn't break down naturally or that takes a long time to break

down should never be put into the septic system. Materials such as oils, grease,

and fat, disposable diapers, tampons and their holders, condoms, paper towels,

facial tissues, cat box litter, plastics, cigarette filters, coffee grounds, egg shells,

and other kitchen wastes, should never be put into the septic system. You should

also avoid the use of in-sink garbage disposal units.



Biological: Because septic systems rely on microscopic organisms to break down

the waste material, it is important that you don't “poison” these organisms. Even

small amounts of paints, solvents, thinners, nail polish remover and other common

household compounds flushed or poured down the drain can kill the organisms that

break down organic material. Laundry bleaches, toilet bowl cleaners and caustic

drain openers can also slow the treatment process, allowing sewage to pass through

to the leaching bed without proper treatment. However, moderate use of these

materials should not interfere with the operation of the septic system. Some

manufacturers promote the use of septic tank “cleaners”, “starters” or “enhancers”

to aid in the digestion of the waste. These products are typically of little value, and

in some instances may actually kill essential bacteria, so they are not

recommended.



Physical: The most common reason for system failure is not having

the solids removed from your septic tank on a regular basis. When the

holding tank is not pumped out frequently enough, the solids can enter

the pipes leading to and from the tank. This can cause sewage to back

up into the house or cause the drainage system to fail as the pipes and

soil become congested. These problems are often costly to fix, pose a

danger to public health, and are a significant source of water pollution.

Seepage from inadequate or failing septic systems can contaminate both ground and surface waters.

Malfunctioning septic systems are currently one of the leading cause of groundwater pollution in

Oregon. Multiply this by the other Americans on septic systems and you can just imagine the potential

for groundwater contamination. Currently, one-fourth of U.S. homes are using septic systems, with

more than 4 billion gallons of wastewater being dispersed below the ground’s surface each day.



Wastewater contains several undesirable pollutants. Pathogens such as viruses

or bacteria can enter drinking water supplies creating a potential health hazard.

Nutrients and organic matter entering waterways can lead to tremendous growth

in the quantity of aquatic microorganisms. Metabolic activity of these microbes

can reduce oxygen levels in the water causing aquatic life to suffocate. You can

prolong the life of the septic system by controlling the amount and timing of

wastewater you put into the system. Reduce the use of phosphate-based

detergents, soaps and cleaners. The phosphorus in detergents doesn't break

down in a septic system. When the phosphorous leaches into the ground and into

nearby bodies of water, it can promote algae growth and can impair water

quality and fish habitat.







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SEPTIC SYSTEMS

Septic System Failure & Repair

Improper Design and Installation

Some soils provide excellent wastewater treatment; others don’t.

For this reason, the design of the drainfield of a septic system is

based on the results of soil analysis. Homeowners and system

designers sometimes underestimate the significance of good soils

or believe soils can handle any volume of wastewater applied to

them. Many failures can be attributed to having an undersized

drainfield or high seasonal groundwater table. Undersized septic

tanks – another design failure – allow solids to clog the drainfield

and result in system failure.



If a septic tank isn’t watertight, water can leak into and out of the

system. Usually, water from the environment leaking into the

system causes hydraulic overloading, taxing the system beyond

its capabilities and causing inadequate treatment and sometimes

sewage to flow up to the ground surface. Water leaking out of the

septic tank is a significant health hazard because the leaking

wastewater has not yet been treated.



Even when systems are properly designed, failures due to poor installation practices can occur. If the

drainfield is not properly leveled, wastewater can overload the system. Heavy equipment can damage

the drainfield during installation which can lead to soil compaction and reduce the wastewater

infiltration rate. And if surface drainage isn’t diverted away from the field, it can flow into and

saturate the drainfield.



Septic System Repair

If you notice any of these problems, it is important that you take action immediately to protect your

health and your environment. Contact one of the following licensed professionals to confirm the

location and possible cause of the failure. They will also propose a repair solution.

1. A certified Installer is usually the first and best person to contact to investigate

the problem but a licensed Designer or qualified professional Engineer is also

available.

2. A certified Pumper/Sludge-hauler can inspect the septic or pump tank to

investigate causes of septic system backups or slow draining fixtures. They

may recommend contacting a certified repair person if the septic system is

failing.

3. County septic inspectors can confirm the failure by inspecting the septic system.

In Jackson County, contact Chuck Henke at 774-6931. In Josephine County

contact Chuck Costanzo at 471-2850.



Repairs can range from clearing a few lines, to replacing entire leaching beds and removing

contaminated soil and costs can vary from a few hundred dollars to several thousands of dollars.

You are also required by law to report any problem to your Local Health Unit before proceeding with

repairs. A final inspection will need to be carried out and a septic Repair Permit and a County Use

Permit granted before you can legally use a new or altered septic system.









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SEPTIC SYSTEMS

Septic System Contractors

JACKSON COUNTY









Septic Systems—Cleaning, Inspection & Pumping

A Affordable Royal Flush Septic Tank Cleaning 772-3389

A Fresh Way Septic Tank Cleaning Service 772-6954

Cook’s Septic Tank Pumping 772-9484

D & D Sanitation 773-6217

Jefferson State Pumping 857-2923

Jim’s Septic Service 776-2324

Mr. Rooter Plumbing 773-8833

Roto-Rooter Septic Tank Service 772-6766









Septic Systems—Construction

Bill’s Backhoe Service 773-3995

Braun Backhoe Service 826-9365

Don’s Tractor Service 840-0228

Dunlap Septic Excavation 770-6744

Express Excavation 560-1114

Fox Building Company 826-9306

George Hepner Dozer & Backhoe Service 826-4369

Mathews Land Developing 831-1010

Dan Matlock Backhoe & Dozer Service 878-3176

Mountain View Rock 826-7367

Oregon Septic Systems 535-1619

Tobiasson Excavation 482-7554









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SEPTIC SYSTEMS

Septic System Contractors

JOSEPHINE COUNTY









Septic Systems—Cleaning, Pumping & Inspection

A Affordable Royal Flush Septic Tank Cleaning 479-6935

A Fresh Way Septic Tank Cleaning Service 476-8477

Cook’s Septic Tank Pumping, Central Point 772-9484

D & D Sanitation 474-6210

Elmer’s Septic Service, Cave Junction 592-6307

Honey Truck 479-6918

Jefferson State Pumping, Medford 857-2923

Jim’s Septic Service Pumping & Cleaning 476-9726

Mr. Rooter Plumbing 476-8216

Rogue Valley Pumping Septic Services 471-9281

Roto-Rooter Septic Tank Service 772-6766









Septic Systems—Construction

Bill’s Backhoe Service, Medford 773-3995

Braun Backhoe Service, Eagle Point 826-9365

Dunlap Septic Excavation 582-3694

Express Excavation, Prospect 560-1114

General Excavating, Selma 597-4355

Littlefield Excavating & Backhoe 479-2802

Mace’s Excavation & Construction 479-6576

Mr. Ed’s Backhoe Service 476-2821

Gary Peterson 479-2981









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SEPTIC SYSTEMS

Preliminary Site Development Plan









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SEPTIC SYSTEMS

Site Development Plan—Equal Distribution









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SEPTIC SYSTEMS

Site Development Plan—Serial Distribution









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SEPTIC SYSTEMS

SEPTIC SYSTEMS

Content Index

Additives 21

AdvanTex System 18-19

Alternative Treatment Technologies 18-19

As-Built Drawing 4

Authorization Notice 7

Biomat 3

Buyer Considerations 7

Causes of Septic System Failure 25-27

Certificate of Satisfactory Completion 11

Conventional Trench System 14

Drainfield 3-4,12-14,21-22

Diversion Distribution Boxes 14

Drop Boxes 14

Effluent 2-3

Equal Distribution System 14,31

Failures, Signs of 25

Inspections 5, 7

Installing a New Septic System 8-19

Intermittent Sand Filter System 16

Jackson County Septic Contractors 28

Josephine County Septic Contractors 29

Lift Tank 16

Locating System Components 4

Maintenance 5

Major Alteration Permit 24

Minor Alteration Permit 24

Orenco Advantex System 18-19

Permit Process 8-10

Pools & Hot Tub Considerations 12, 22

Pre-Cover Inspection 11

Preliminary Site Plan 30

Preventative Maintenance 20-23

Pumping the Septic Tank 5-6

Recirculating Sand Filter System 16

Repair Permit 27

Sand Filter System 15-18

Secondary Treatment 3

Septic Tank 2, 4-7, 18-19

Septic Tank Inspections 7

Serial Distribution System 14, 32

Setback Requirements 12

Site Evaluation 8-9

Soil Evaluation 9-10

Steam Crossings 24

Test Pits 8-9

Use Permit 27

Wastewater Collection 1

Wastewater Separation 2

Wastewater Distribution 3

Water Usage 20

Water Softeners 23-24









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Acknowlegements

Thank you to the following people, who donated their time to provide material

information, and / or review and edit this guidebook. You were instrumental in

seeing to it that the information provided herein was accurate and up-to-date.



Chuck Costanzo, Department of Environmental Quality, Grants Pass, OR

Chuck Henke, Jackson County Roads, Parks & Planning, Medford, OR

Penny & Perry Dunlap, Dunlap Septic, Rogue River, OR

Roury Summers, Roto-Rooter, Medford, OR

Dick Florey, Florey Soils Consulting, Medford, OR





The following resources greatly contributed

to the compilation of this information guidebook.



A Homeowner’s Guide to Septic Systems, Environmental Protection Agency



Septic Systems, Oregon Department of Environmental Quality



Septic System Owner’s Guide, University of Minnesota Extension Service



Your Septic System, Canadian Mortgage and Housing Corporation



How Septic Systems Work, Virginia Cooperative Extension, Virginia

Polytechnic Institute and State University



Septic System Maintenance, Ohio State University Extension



How to Locate Your Drainfield, Thurston County Environmental Health

Division, Olympia, Washington



Intermittent & Recirculating Sand Filters, National Small Flows Clearinghouse



Septic System Diagrams, Landmark Inspection Service, Alva, Florida









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