On-Site Wastewater


Septic Tank Systems

What is A Septic Tank System?
A septic tank system consists of a large, watertight tank that receives wastewater from the home plumbing system. The tank is followed by an underground drainfield consisting of a network of perforated pipe and drainage media or chambers for distributing partially treated water from the septic tank to the soil for final treatment and disposal.

How Does It Work?
Septic tanks contain bacteria that grow best in oxygen-poor conditions. These bacteria carry out a portion of the treatment process by converting most solids into liquids and gases. Bacteria that require oxygen thrive in the drainfield and complete the treatment process begun in the septic tank. If the septic tank is working well, the wastewater which flows out of the tank is relatively clear, although it still has an odor and may carry disease organisms.

Operation and Maintenance
After the septic tank system is placed in service, proper operation and maintenance of the system will ensure continued efficient service and prevent sudden replacement expenses. The septic tank and drainfield are designed and installed to handle a maximum calculated daily sewage flow. Consistently exceeding the design flow will eventually overload the system and cause failure. The tank may receive new solids faster than it can treat them and the drainfield may become saturated from excessive water use. Various products are on the market which are said to start, accelerate or improve the action in the septic tank. Since all necessary bacteria are already present in the sewage entering the system, such products are not recommended.

Maintenance of a septic tank will depend largely on the daily sewage flow and individual household wastewater characteristics. With ordinary use and care, a septic tank should not require pumping out more than once every three to five years. It should, however, be inspected to determine the depth of accumulated sludge and grease. Waste from a kitchen garbage disposal unit puts an extra load on a septic tank system. If a garbage disposal is used, the capacity of the tank should be increased to handle the increased solid wastes. The tank may also require more frequent pumping to remove accumulated solid waste buildup. Failure to pump out a septic tank system when indicated will result in solids or greases overflowing into the drainfield, which in turn may become clogged and stop functioning. In this event, not only will the tank have to be pumped out, but the drainfield may also have to be replaced. Septic tanks can only be pumped by certified septic tank cleaning firms permitted by the NCDENR Division of Waste Management.


Location
Contaminants can travel long distances in some soils. Therefore, drinking water wells should be located at least 100 feet from any part of a septic tank system, except in situations where space limitations and other site-planning considerations allow a reduction of up to 50 feet.

Preventing Failures
Septic tank systems fail when the drainfield does not dispose of sewage as rapidly as it is being added to the system. Thus, improvements that reduce the amount of incoming water or improve the quality of wastewater passing through the system will increase the system's longevity. Other important considerations include the following:

  • A drainfield can be damaged by compaction due to vehicular traffic and can be blocked by excessive shrubbery or tree root growth. The drainfield should be unobstructed and seeded with grass. Grass and sunlight aid evaporation.
  • Washing machines are responsible for large volumes of water entering the septic tank. The surge of wash water can create turbulence in the tank which increases the amount of solids flushed into the drainfield. Space washings throughout the week rather than doing many loads at a time.
  • Cooking oils and grease are trouble makers. The type of bacteria found in septic tanks and drainfields do not survive or function well in solidified grease. Grease and cooking fats should never be washed down the sink drain. Save grease in jars or cans for disposal in the garbage.
Do's
  • Know the location and capacity of your septic tank system. If you have a copy of your original permit, keep it available for future reference.
  • Have tank pumped when the combined depth of the sludge and scum equals 1/3 of the tank liquid volume.
  • Install the system so that rainfall and surface water will flow away from the drainfield. · Grow grass above the system.
  • Install water conservation fixtures or devices to reduce the total volume of water entering the system.
  • Keep plumbing fixtures such as toilets and faucets in good repair to prevent leakage and wasting of water
  • Keep copies of maintenance receipts
Don'ts
  • Never flush paper towels, newspapers, wrapping paper, rags or sticks into the system.
  • Never over-use ordinary household cleaning chemicals that will be flushed into the system.
  • Never pour out or empty hobby or home industry chemicals into the system.
  • Never allow grease or other bulky waste to enter the system.
  • Never flush toxic materials such as pesticides into the system.
  • Never plant trees or shrubbery in the drainfield.
  • Never allow vehicles (cars, trucks, etc.) to drive across or park on the drainfield. (Protect it from being crushed.)
  • Never waste water.
  • Never use chemical solvents to clean plumbing lines or a septic tank system.



Procedure For Obtaining Septic System Permits

An on-site wastewater system involves the collection, treatment, and disposal of wastewater in single or multiple components. These include a privy, septic tank system, public or community wastewater system, mechanical or biological wastewater treatment system, any other similar system, and any chemical toilet used only for human waste. A person owning or controlling a residence, place of business or place of public assembly shall provide an approved wastewater system. The Department regulates the installation, collection, treatment, and disposal of septic systems and other types of wastewater systems in order to render them ecologically safe and to protect public health. Governing regulations include The Laws and Rules for Sewage Treatment and Disposal Systems of the North Carolina Department of Environment and Natural Resources, Division of Environmental Health(NCDENR-DEH).

Application and Site Preparation
The permitting process is specific to the type of construction being applied for; new expansion, reuse or repair. All permitting must be completed before any installation takes place. Please feel free to call the Carteret County Health Department if there are any questions.

The lot owner or authorized representative will need to fill out an application for an Improvement Permit. The completed application authorizes the Environmental Health Specialist to evaluate the property. To expedite the Soil/Site evaluation process, please ensure you have completed the entire application thoroughly. The following information is required on the application:
  1. the applicant and the owner's (if different) name, mailing address and phone number;
  2. location of the property;
  3. description of existing and proposed facilities and structures;
  4. plat of property or site plan;
  5. number of bedrooms and number of occupants, number of persons served, design daily flow, wastewater characteristics, and other factors required to determine wastewater system design;
  6. type of water supply, including the location of any proposed or existing well(s); and
  7. signature of owner or owner's representative.
  8. if there are existing or proposed easements, rights of way, encroachments, buffers, the property contains designated wetlands or other areas on the property with legal restrictions.
The property will need to be accessible and properly marked. The application brochure specifically addresses how to prepare the site. If anything is not completed or marked properly when the Environmental Health Specialist arrives to evaluate the property, he/she will be unable to perform the evaluation. This will result in a revisit fee to the property owner and also delay issuance of permits.

Site Evaluation
The soil/site evaluation is the first step in determining if a site is suitable for a wastewater system. This evaluation is also used when there is an expansion of an existing wastewater system.

During the site evaluation, the Environmental Health Specialist gathers information about the site that includes topography and landscape position, soil characteristics, soil wetness, soil depth, restrictive horizons, and available space. The Environmental Health Specialists uses the facts they collect at the site evaluation to help determine a specific lot's ability to support the septic tank system requested on the application.

Improvement Permit
An Improvement Permit is issued after the Environmental Health Specialist has determined that the site is suitable and that a system can be installed to meet the provisions of the Laws and Rules for Sewage Treatment and Disposal Systems. Information on the Improvement Permit includes:

  1. A diagram representing the location of the initial system and reserve area with dimensions and setbacks to fixed reference points;
  2. locations of existing and proposed well(s) and applicable water lines;
  3. location and description of the facilities, structures, driveways, and other proposed improvements; and
  4. the proposed initial and reserve system types including permit conditions and site modifications.

Other conditions included on an Improvement Permit may include submittal of plans and specifications, or legal agreements or easements. The Improvement Permit is valid for 60 months from the date of issue or indefinitely when a plat is provided. Improvement Permits are subject to revocation if the intended use changes, the site and soil conditions are altered, the design wastewater flow changes, or the wastewater characteristics are increased. Building permits can not be obtained with the Improvement Permit.

Denial of Improvement Permit
When an application for a wastewater system permit is denied a letter is issued advising the applicant of the reasons for the unsuitable classification. The Environmental Health Specialist must include consideration of possible site modifications, and modified, experimental, innovative, accepted systems, components or devices, or alternative systems prior to denying the site. The applicant is offered any options that may be available for reclassification of the site. In addition the applicant may request, in writing, an informal review by the Environmental Health Program Specialist and also by the NC Department of Environment and Natural Resources Regional Soil Specialist. A formal appeal for a contested case hearing requires that a petition be filed with the Office of Administrative Hearings(OAH) within 30 days of the date of the denial letter. More information on appeals may be found at the OAH website.

Authorization for Construction Permit
The Authorization for Construction (Construction Authorization) permit is issued when the conditions required on the Improvement Permit and the Laws and Rules for Sewage Treatment and Disposal are met. The Construction Authorization contains conditions regarding system type, system layout, location, installation requirements and maintenance and operation requirements. The Construction Authorization is valid for a period equal to the period of validity of the Improvement Permit and shall not exceed 60 months.

The property owner is responsible for ensuring that the Construction Authorization is obtained and is valid prior to the construction, location, or relocation of a residence, place of business, or place of public assembly. The wastewater system contractor is required to install the wastewater system as specified on the Construction Authorization permit. A Construction Authorization may be revoked or suspended if the site has been altered, or the information submitted in the application is found to have been incorrect, falsified or changed.

Operation Permit
The Operation Permit is issued when the Environmental Health Specialist completes a final system inspection and determines that all the conditions of the Improvement Permit, the Construction Authorization and installed system is in compliance with the Laws and Rules for Sewage Treatment and Disposal Systems. The issuance of the Operation Permit is required prior to release of the Certificate of Occupancy (CO) by the Building Inspector.

The Operation Permit includes the conditions for system performance, operation, maintenance, monitoring and reporting. Some septic systems such as low pressure pipes, peat filters, fixed media filters, and other pretreatment systems require contracts between the owner and a certified subsurface operator and/or wastewater operator to maintain and operate the system for as long as the use of the system is required. Noncompliance of these requirements can results in permit suspension or revocation or other legal remedies as specified in the Rules.

An Operation Permit shall be valid and remain in effect for a system provided:

  1. The use of the facility remains unchanged,
  2. the quantity and quality of the wastewater is unchanged,
  3. no malfunction is found,
  4. the conditions of the Operation Permit are complied with, and the operation permit has not expired.
Operation Permits for Type V and VI systems (Pretreatment) are valid for a period of 60 months. Renewal applications are required six months prior to the expiration.

Expansion of an Existing System
A wastewater system expansion is required when an existing facility has a proposed change or addition that increases the water use. The increase in water use is based on Rule .1949, Sewage Flow Rates for Design Units. Examples of flow increases are addition of a bedroom(s), increase in retail sales area, or adding restaurant seats or food stand prep area. Expansions of wastewater system must be in compliance with the current Rules.

The owner must fill out an application for an Improvement Permit and describe the existing facility and ALL proposed changes or additions. An expansion also requires locating the existing septic tank, drain field and repair area. The original permit issued by the health department, if available, will facilitate finding the system. An information request form may be submitted to the health department to find a permit.

An Environmental Health Specialist will go on-site to evaluate the proposal and to inspect the existing system to ensure that it meets State requirements. An Improvement Permit and subsequently a Construction Authorization will be issued if the existing system and the site are suitable for the proposed expansion.

Relocation of an Existing System or a Repair Area
The relocation of a system, the repair area or a component of the system may be required in such cases as a building addition, the addition of a swimming pool, a driveway or parking area or other permanent structure or site disturbance. The owner or authorized agent must submit an application for an Improvement Permit. The application process is the same as required for expansion of an existing system. The proposed relocation of a system, repair area or component requires compliance with the current Rules. When a system, repair area, or component can not be relocated due to unsuitable soil or site characteristics then the permit is denied and construction or site disturbance can not occur in the proposed area.

Change of Use
A change of use application is needed when the use of a wastewater system is proposed to be changed to a higher strength wastewater, industrial process wastewater, or a use that is not consistent with the permitted use. High strength wastewater requires a higher level of treatment and a more stringent soil and site evaluation. A system designed for domestic wastewater, such as a single family home or office building has not been designed to handle the wastewater from a restaurant.

Existing System Authorization
An application for an existing system authorization, typically mobile homes or replacing mobile home with a house, must include a site plan indicating the locations of the proposed facility, setbacks to property line(s) or other fixed reference point(s), the proposed use and design flow, the location of the existing system, and the location of all water supplies. The original permit issued by the health department, if available, will facilitate finding the system. An information request form may be submitted to the health department to find a permit. The septic tank, proposed structure(s), and water lines and/or wells must be located and staked on the property. In some cases it may be necessary to uncover the septic tank and the distribution box.

Upon determining that the existing wastewater system and system components has a valid Operation Permit and is being operated and maintained as specified in the Laws and Rules for Sewage Treatment and Disposal and any permit conditions, and that a proposed change of use, location, relocation, or addition to the facility, or connection to the system is in compliance with the Operation Permit and the Rules, the Environmental Health Specialist will issue a written authorization for the connection to the existing system.

Repairs
Septic tank systems do not work forever. If you are having problems with your septic tank system, take a look at the questions below. Answer them with “yes” or “no”; even if your answer is “sometimes”, still answer with a “yes”.
  • Is sewage or effluent being discharged from your septic tank system onto the surface of the ground, surface waters, or directly into the groundwater?
  • Is sewage or effluent backing up into your home, facility, drains, or septic tank?
  • Is there sewage or effluent within 3" of the finished grade over the septic tank system?
  • Is it necessary to have your septic tank pumped more than once per month to avoid answering "yes" to one or more of the above questions?
If you answered “yes” to any of the above questions, you have a malfunctioning wastewater system. The owner must fill out an application for a repair permit and complete a simple questionnaire. The answers to the questionnaire will assist the Environmental Health Specialist in determining causes of the problem. The Specialist will evaluate the site and the existing system before issuing a repair permit. In some cases the system may be fixed by repairing a leaky toilet or fixture, or diverting surface water. A repair permit is not required in these cases.

Repair permits issued for sites with poor soil conditions or limited space are based on best professional judgement to provide the best functioning system possible and protect the environment and public health. In most of these situations it is necessary that the system owner take additional measures to ensure the future performance of their system. These measures include practicing good wastewater system practices. This information and more can be found in the Septic System Information for Homeowners booklet.

Whatever the cause it is important to remember that sewage contains viruses and bacteria that are dangerous and should not be ignored.



Applications/Forms
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