Wayne, Maine
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Septic System Questions And Answers

Here are a few of the questions we commonly receive regarding septic systems including their design and installation.  If you have a question and don’t see it on this page, please feel free to contact us, we’ll be happy to answer any other questions you may have.

All human structures containing plumbing facilities generate sanitary wastewater from toilets, sinks, dishwashers, washing machines, and other plumbing fixtures. A properly operating septic system will treat the wastewater in a septic tank to remove solid materials and convey the partially treated water into a subsurface leachfield where it will receive further treatment within the soil before it is eventually dispersed into the ground. Virtually all the wastewater that enters a septic system is discharged into the groundwater where it eventually drains to surface water bodies or groundwater wells, so it is vital that the wastewater receive adequate treatment in the septic system before it enters the groundwater. Modern septic systems are designed to provide the necessary treatment; old systems, while they may make the wastewater go away, do not necessarily provide a high level of treatment before reaching groundwater.


This site provides additional information on the functioning of septic systems.

Any human occupied structure that will have internal plumbing is required to have a means of disposing of wastewater. Three means of wastewater disposal are a public sewer, private septic system, or an overboard discharge licensed by the Maine Department of Environmental Protection. Overboard discharges are in a special category and are no longer allowed for new developments, meaning that for any site that is not served by a public sewer, a privately owned septic tank-leachfield system is necessary.

Septic system design in Maine must be done by a licensed site evaluator. The state regulations covering the state septic system program are 144A CMR 241, MAINE SUBSURFACE WASTEWATER DISPOSAL RULES. The rules cover details of site evaluations and design and construction of wastewater disposal systems.


Contractors are not required to be certified in the installation of septic systems and, in fact, a property owner is entitled to construct their own system. Maine does have a voluntary certification program for contractors who attend training sessions covering construction techniques, erosion control, and state environmental regulations. A list of certified septic system installers can be found here.

The Department of Health and Human Services, Maine Center for Disease Control and Prevention, Division of Environmental Health is the state agency that oversees the administration of the septic system program, including licensing of site evaluators who design septic systems. The Department of Environmental Protection does not have jurisdiction over the septic system program, but the two departments work closely together to resolve pollution problems caused by malfunctioning septic systems.


The DHE delegates enforcement of the septic system program to individual towns through the Local Plumbing Inspector, who is licensed by the state to inspect internal plumbing and septic system construction. Since the LPI is an agent of the state for septic system issues, property owners need to interact directly with the LPI to obtain permits and all other septic system issues. The town may also have a Code Enforcement Officer, who often also serves as the Local Plumbing Inspector, to enforce other town codes such as shoreland zoning and building codes.


In unincorporated or unorganized areas of the state the local is done through the Maine Land Use Planning Commission (LUPC), who provide similar services as the municipality. A Local Plumbing Inspector should be available to issue permits and conduct inspections in unorganized areas.


The Licensed Site Evaluator who designs the septic systems is a private consultant and is not a representative of a government agency.

Although you may hear the term “perc” or percolation test referred to in septic system design, the actual test, which consists of filling a hole with water to determine the soil drainage, is considered obsolete in Maine. Septic systems are designed by a licensed site evaluator who conducts and site evaluation which examines all the features of the site including the soil drainage conditions to determine the best type septic system for the particular site.

An external plumbing permit from the Local Plumbing Inspector(LPI) is the generally the only construction permit needed to construct a septic system. The plumbing permit consists of the system design on an HHE-200 form with a permit number issued by the LPI. The plumbing permit also covers any state environmental NRPA permits needed for construction of the project.


Other permits which may be necessary as part of a project done in conjunction with the septic system are a New or Replacement System Variance(prepared as part of the plumbing permit application), Minimum Lot Size Variance, Seasonal Conversion Permit, NRPA Permit, Army Corp of Engineers permit, and internal plumbing permit. In addition, individual towns may have their own permit requirements which should be verified locally. The town Code Enforcement Officer should be contacted for further information.

There are four steps to designing and building a septic system:


  1. The system must be designed by a professional known as a Licensed Site Evaluator. Site Evaluators are private consultants licensed by the State of Maine who charge a fee for their service. A list of site evaluators who practice locally is available from the Local Plumbing Inspector of the town where the property is located. A statewide list of evaluators is also found here. The site evaluator will provide a system design in a standard format called an HHE-200 form.
  2. A permit must be obtained from the Local Plumbing Inspector of the town where the system will be constructed. Three copies of the system design(HHE-200) are brought to the Local Plumbing Inspector(LPI) and a permit sticker will be attached after the permit fee is paid. The LPI will keep two copies of the design for local and state records, and give one copy back to the applicant. You will also need to notify the LPI of the schedule for installing the system so that inspection can be arranged.
  3. Construction is normally done by an excavating contractor. It is permissible to construct the system yourself provided that the installation is done in accordance with the approved plans. It is recommended that two or more estimates be obtained from reputable contractors to ensure that the best price is obtained. The cost of the septic system is influenced by a number of factors including the contractor’s schedule and source of materials.
  4. The system needs to be inspected by the Local Plumbing Inspector to ensure that it is installed in accordance with the subsurface rules. Inspection of the system by the designer is not normally provided as a basic service, but may be available in addition to the design. Because inspections must be coordinated with the construction schedule, the contractor should be responsible for scheduling inspections and should be aware of who to contact to do so. The LPI will initial the HHE-200 when inspections are conducted as evidence that the proper inspections were performed.

The site evaluation is performed by a state licensed site evaluator to determine the appropriate septic system design to handle wastewater on the property. The site evaluator is a licensed design professional who will charge a fee for this service. The evaluator will visit the site and examine site characteristics which affect the design and performance of a septic system. Some of these features are:


  • The size of the property and location of the property lines.
  • The location of water bodies including the ocean, lakes, rivers, streams, drainage areas, and wetlands.
  • Zoning and local ordinances affecting the use of the property.
  • Surface drainage patterns.
  • Soil conditions on the site.
  • The location of existing wells and structures on or adjacent to the site.
  • Steepness of the site.
  • The presence of bedrock.


It is the responsibility of the property owner to accurately identify the location of property lines and easements, and man made structures such as buildings, wells, and underground utilities on the site. In addition, the site evaluator will need to know the nature of the wastewater to be treated in the septic system. This is often based on the number of bedrooms in the home, and should be carefully considered since it will affect the size, and cost, of the leach field, as well as possibly limiting expansion in the future.


After consideration of all the site conditions, the site evaluator will recommend the appropriate type of system, or may present alternatives for the property owner to choose from. In general the system should be located on the downhill side of the building to allow wastewater to flow by gravity into the system without the use of a pump.

No. Systems can only be designed by a Maine Licensed Site Evaluator, even for your own system. In order to obtain a license the evaluators must demonstrate that they have the ability to properly evaluate site conditions and design a septic system in compliance with Maine rules and standards.

Individuals may construct their own septic system if they have the capability to do so. Construction may require the use of heavy equipment and must be built in accordance with the plans and pass inspections by the Local Plumbing Inspector.

Most contractors advertise online, but it is a good idea to obtain references from other jobs that they may have done. The site evaluator who designs the system or the Local Plumbing Inspector who issues the permit may have the names of excavating contractors that they are familiar with.


Maine does not require that contractors be certified or licensed to install septic systems, but the State does have a voluntary certification program for contractors. Certification indicates that the contractors have received training in septic system installation and erosion control techniques. A lists of contractors certified in septic system installation may be found here. Contractors certified in erosion control are listed here.  By law, all earthwork done in within shore-land zoning must be done by a contractor certified in erosion control.

Septic system inspections are done by the Local Plumbing Inspector of the town where the system is constructed. The inspector will conduct a minimum of two inspections, one after the site has been opened and is ready for the installation of the system, and the second after the system is installed but still uncovered. The LPI may be willing to conduct additional inspections for a fee.


Inspection is not typically included as part of the design done by the Licensed Site Evaluator who designed the septic system, but may be negotiated for an additional fee.


Inspection of the system by the Licensed Site Evaluator who designed it is not normally provided as a basic service, but may be available as an additional service.

The main factors that affect the design of a septic system are the estimated volume of wastewater flow, the type of soil on the site, and the depth to factors that affect drainage such as groundwater or bedrock.


The size of the subsurface disposal bed or leachfield is determined by the estimated volume of wastewater flow and by the soil type where the leachfield will be constructed. For residences, the flowrate is generally estimated based on the number of bedrooms and the size of the system is proportional to the number of bedrooms. The number of bathrooms does not affect the size of the leachfield. The second factor that affects the size of the leachfield is the soil type. Depending on the texture and drainage of the soil the leachfield size of small, medium, large, or extra-large will be determined. These two factors determine the actual size of the leachfield in square feet. Leachfields are usually rectangular with long, narrow beds being the best configuration because they spread the water out more efficiently.


The elevation of the leachfield is determined by the depth to limiting factors such as groundwater table or bedrock. Limiting factors prevent or impede wastewater from draining away from the leachfield and the subsurface rules require that the bottom of the leachfield be raised 12 to 24 inches above the limiting factor. In addition, this separation between the bottom of the leachfield and the limiting factor ensures that the waste receives maximum treatment before it enters the groundwater table. Since the seasonal high groundwater table or depth to ledge in Maine is frequently found at depths of less than 36 inches, most subsurface disposal beds are raised up to some extent, and may be mounded up three or four feet above the original ground on sites that or wet or contain shallow bedrock.


Local and Town Zoning Ordinances may also affect the suitability of a site for development or construction of a septic system. It is always a good idea to ask the Town Code Enforcement Officer what ordinances may apply to your property.

A drywell is a shallow pit filled with stone or perforated well tile that holds a volume of water within the well and allows it to trickle out through the sides of the pit. When used to dispose of wastewater a drywell is also known as a cesspool or seepage pit. This type of system cannot be legally installed in Maine because the wastewater does not receive adequate treatment and may pollute the groundwater.


Separated laundry disposal systems may be used if designed by a licensed site evaluator. The requirements for a separated laundry system are the same as for any other wastewater disposal system except that a septic tank is not required before the leachfield. Because there is no preliminary treatment in a tank, this type of system is susceptible to plugging due to lint. A separated laundry system may be an economical alternative to replacing the entire leachfield when the performance of the septic system is sluggish, but site conditions may prevent this from being a satisfactory alternative.

Septic systems contain two parts:


  • The septic tank
  • The subsurface disposal area, or leach field


The purpose of the septic tank is to remove solids and grease before discharging partially treated wastewater into the leach field for further treatment and disposal. The tank acts as a settling basin and allows heavy solids to settle to the bottom, and floating material such as grease to rise to the top. The outlet pipe is placed behind a baffle wall which causes liquid in the tank to be drawn from the middle rather than the top, preventing the floating scum layer from overflowing out the effluent pipe. Tanks must be pumped out periodically to remove the solids and scum which collect to prevent them from washing out of the tank and causing the leach field to fail.


Tanks are usually made of concrete, although plastic tanks are available. Plastic tanks are lightweight and may be carried by two people, but are more easily damaged than concrete and need to be secured so that they won’t float when empty. Concrete tanks may be more likely to leak because they contain a seam between the two halves of the tank. Special one piece tanks are available when leakage into the tank is critical.


Following treatment in the tank, effluent is discharged into a large subsurface bed or leach field. Depending on the elevation of the leach field it may be necessary to lift the septic tank effluent into the leach field with a pump.


The purpose of the leach field is to distribute the wastewater over a large area so that it will receive further treatment by soil bacteria before trickling out into the natural soil and mixing with groundwater. Purification of the wastewater occurs partially through natural processes from microorganisms living in the leach field, and finally be dilution of the final effluent as it seeps into the groundwater table. In order to protect health the state code requires that the leach field be separated from wells and water bodies to allow natural processes to fully treat the waste.


The leach field may consist of a large bed of crushed stone and pipe, or it may contain manufactured devices that replace the stone and pipe bed. The bed of stone or other devices create room for the wastewater to be stored until it trickles away into the soil. Stone beds and proprietary devices serve essentially the same purpose, and each have benefits.


Benefits of stone beds are:


  • There are a “tried and true” technology and have been in use the longest
  • Materials or usually easy to obtain
  • May be easier to install
  • May be less costly


Benefits of proprietary devices are(Note that there are a wide array of different proprietary devices and benefits are generalized):


  • May use less land area or fill materials
  • May be easier to install on certain sites
  • Uniform quality of materials
  • May be easier to transport
  • May be designed for vehicular traffic
  • May provide additional treatment of wastewater prior to discharge to the soil


The specific site conditions are the major consideration for choosing the type of leach field materials.

Septic systems are raised up to improve performance and ensure that complete treatment of the wastewater occurs before it enters the ground. The State of Maine Subsurface Wastewater Disposal Rules require that the bottom of a disposal area be separated from a limiting factor such as the seasonally high groundwater table or bedrock by 12 to 24 inches. This means that the top of the final grade over the leachfield will be 36 to 48 inches above the depth to the limiting factor. The state code allows septic systems to be constructed on soil with a depth to limiting factor of as little as twelve inches, so raised beds are not uncommon.

In general it is not recommended that a system be driven on by cars or heavy vehicles. Lawns tractors can be used to mow the leachfield without danger. In cases where there is no alternative it is possible to design a system that will support traffic. A special heavy duty septic tank, and reinforced concrete leaching chambers will support traffic without structural damage. Compaction of the soil under the chambers due to weight and vibration may cause the system to fail prematurely, however.

Operation and maintenance of a septic system consists of avoiding or minimizing the disposal of materials that can shorten the life of the system, and pumping the septic tank before solids build up too high in the tank.

The following can shorten the system life or impair its performance:


  • The use of a garbage disposal is never recommended with a septic system. Although they are permitted by the state code and special design features can be added to help minimize their impact, they will most likely shorten the life of the septic system to some extent.
  • Water conservation, including low water use plumbing fixtures, should be used. Septic systems are designed to handle the water needs of an average user and may not function properly if excessive volumes of water are used. In addition, the system will begin to handle less water as it ages. It is prudent to avoid unnecessary water use with a septic system.
  • It is recommended that laundry loads be spread out over more than a single day if many loads are done to avoid overloading the system. It is also recommended that liquid rather than powdered laundry detergent be used because powders contain solid material that can settle out in the septic system.
  • Avoid dumping any oil, grease, or fat into the septic system. Although the septic tank is effective in trapping these wastes if they solidify in the tank and float to the top, they can quickly clog the soil of the leach field if they pass through.
  • Restaurants have historically had septic system problems due to grease in their waste.
  • Do not dump any toxic materials down the drain. This includes chlorine bleach or other cleaners, chemicals, or petroleum products. The septic system depends on living microorganisms to treat the wastewater before it enters the groundwater. Materials that are dumped in toxic quantities can result in contaminated wastewater seeping into the groundwater or even failure of the septic system.
  • The use of septic tank additives is not recommended.


Aside from using the system sensibly, the septic tank will need to be pumped out periodically to avoid accumulated material from washing out into the leach field. The actual need for pumping varies depending upon use, but is generally recommended about every three years. If a garbage grinder is used the tank should be pumped out every year. Septic tank pumping companies may be able recommend a pumping interval after pumping the tank, and may send reminders that pumping is due. Although there is a cost to pump the tank, it is small in comparison to the cost of a replacement leach field which could result if pumping is neglected.

The state plumbing code allows only a few alternatives to conventional septic systems:


  • Separated Laundry System – Laundry waste may be discharged into a separate leach field from the rest of the household waste. A treatment tank is not need for a separated laundry system but the disposal area must still be designed by a site evaluator. The size of the conventional septic system may be reduced slightly if a separate laundry system is used, but the use of separated systems is rare for new construction. A separated system may be an alternative to help improve the performance of existing septic systems that are draining sluggishly.
  • Alternative Toilet – A number of alternative toilets are available, including composting toilets and pit privies(outhouses). Privies which discharge to the soil need to be designed by a licensed site evaluator. Alternative toilets are only intended to handle the black waste, and other household wastewater, generally called gray water, must still have a conventional system. The state code does not encourage the use of alternative toilets because there is no provision to reduce the size of the conventional septic system that handles gray water only.
  • Primitive System – A primitive system consisting of an alternative toilet and small gray water system may be designed for structures with hand carried water only, but some town codes do not allow such systems. In general they are intended for sites which do not have a source of electricity.
  • Overboard Discharges – These are small treatment plants that treat and disinfect wastewater before discharging it to a surface water. They require a license for the Maine Department of Environmental Protection. They are no longer allowed for new development but may be permitted for existing properties that have historically had a discharge and have no viable alternative.
  • Drip Irrigation System – This type of system treats the waste to a high level and then discharges the clean effluent into the soil through irrigation piping that is buried just below the ground surface. These types of systems can be costly and their performance during the winter is uncertain.
  • Advanced Treatment System – These types of system may be use instead of or in addition to a septic tank.  They treat water to a high level, and can remove nutrients such as nitrogen.  These allow a smaller footprint of the leach field, and may allow a reduction in the setbacks from a water body.  For some sites advanced treatment may be the only alternative available.  Advanced treatment systems cost more initially and have a higher yearly operating cost.

For new construction there is not much financial help other than a conventional construction loan. For a replacement system the potential alternatives are:


  • Home Equity Loan - If the property owner has sufficient equity in the property it may be possible to borrow against the value of the house. Home equity loans will require a mortgage be recorded against the property, and the interest paid may be tax deductible. Most home equity loans have a variable interest rate that changes according to the market rates.
  • Refinancing – Refinancing the existing mortgage can allow money to be borrowed over a longer term and at a fixed rate.
  • USDA Rural Development 504 Program – This is a federal program with grants and loans available for home improvements. For more information click here.
  • Community Action Program – CAP agencies provide services to low income families on a county wide basis. They are a potential source of low income loans. For a list of CAP agencies click here.
  • Well and Septic Grants – Some towns in the state, in Aroostook and Washington Counties, have received federal community development grants to assist with the construction of replacement wells and septic systems. More information may be available from the town government.
  • DEP Small Community Grant Program – The Maine Department of Environmental Protection has potential grant funding available to replace septic systems that are creating a pollution or public health problem. Information is available here. This funding must be applied for by the municipality.
  • Town Loans – A few towns have set up low or moderate interest loan programs to assist with the construction of septic systems. Information is available from the town government.