Worcester County On-Site Sewage Disposal

Department of Environmental Programs
On-Site Sewage Disposal in Worcester County:

Answers to Frequently Asked Questions

There are more than 5,000 on-site sewage disposal systems (or septic systems) in Worcester County treating approximately 1,500,000 gallons of raw sewage each day. Septic systems are individual wastewater treatment systems used where centralized wastewater treatment is impractical or unavailable.

Properly operating systems remove solids and nutrients that would otherwise pollute groundwater drinking supplies and our streams, rivers and coastal bays. Failing systems can be a significant source of pollution affecting individual wells, public water systems, and the recreational and commercial benefits of local waters. Below are answers to the most frequently asked questions about septic system permitting, installation and care, to help you better understand the permitting process and how your system works.

  1. What is a septic system and how does it work?
    A conventional septic system consists of three main parts: a septic tank, a drainfield, and the soil beneath the drainfield. Waste enters the septic tank where solids separate from the liquids. Contaminants are partially broken down by bacteria present in the tank. Wastewater from the tank is then distributed through a series of perforated pipes in the drainfield. The soil further treats the wastewater before it returns to the groundwater.
  2. I want to put a home on my property that has does not have access to central sewer. What do I need to do?
    If the property has never had a home on it, then a site/soil evaluation, conducted by the County, is required. There is a $300.00 fee for the evaluation. The property owner completes an application giving the Department of Environmental Programs permission to access and test the property. Before beginning the evaluation, the property owner must flag or stake a 10,000 square foot area (septic reserve area) to be tested for sewage disposal suitability. If desired, a private consultant can be hired to provide you with the best possible location to be tested.

    The flagged area will be checked for:
    1. Its relation to drinking water wells, waterways, ditches, slopes, and walls. If problems exist, changes to the proposed area will be recommended;
    2. Soil type: soil borings will be augured;
    3. Water table height: monitoring wells will be installed;
    and, Based on the data collected, tests will be done to determine system design requirements. If the testing results are favorable then the septic reserve area, soil borings, monitoring wells, and "perc" test holes (collectively known as fieldwork) must be located by a registered surveyor.

    If you are replacing an existing residence and a septic system already exists on your property then a site evaluation is not necessary. A detailed site plan showing the distance from existing wells and the septic system/sewage reserve area to the proposed home must be submitted to the Department of Environmental Programs.
  3. I’ve heard this testing can take months or longer, why?
    To be effective, septic systems must work year-round, even when the water table is at its peak. If groundwater rises into the soil beneath the drainfield, the system will not properly treat waste and may not function at all. Therefore, in most cases in Worcester County, soil evaluations must be done during the "wet season".
  4. When is the "wet season"?
    The wet season varies, but generally occurs between January and April when rainfall is substantial and plant uptake is minimal. It is determined by the water levels in monitoring wells located throughout the County.
  5. Why must 10,000 square feet be set aside for sewage disposal?
    The average life expectancy of a drainfield is 10-20 years. In 1972 the State of Maryland passed a law to require that a reserve area large enough for three systems be set aside on a property when a new home is built. This "set aside" provides a sufficient area for system replacement when the drainfield fails.
  6. How can I use the area set aside for sewage disposal?
    You should leave this area as open yard. Both the sewage reserve area and the drainfield area should be kept free of permanent structures (such as a garage or a pool), vehicular traffic, irrigation systems, and utilities. Soil compaction and/or disruption could affect soil permeability, which could adversely affect the drainfield’s function.
  7. Do I have to remove the trees from my reserve area?
    No. Trees can be left in the reserve area until that area is needed for a replacement drainfield. Trees with spreading surface roots (such as maple or willow) should be kept far enough away so that roots do not invade the drainfield.
  8. What is this I hear about pre-treatment units or filters?
    Pre-treatment devices are used to reduce the suspended solids and nutrients that leave the septic tank, go into the drainfield, and eventually into the groundwater. Examples include sand filters, peat filters, and pre-packaged aerobic units. These devices are currently used to alleviate existing problems; however, their use may be required in the future in certain sensitive areas. Pre-treatment units generally add several thousand dollars to the cost of a system, but are effective in increasing the life span of the system and preventing pollution.
  9. When does my on-site sewage disposal approval expire?
    Provided that all fieldwork was surveyor located, the approval does not expire unless there is a regulatory change or there is an alteration to the approved sewage reserve area (for example, soils are excavated).
  10. Is maintenance of my system required?
    Pumping your septic tank every two or three years could avoid a clogged drainfield and early system failure. With systems now costing at least $6,000 to replace, the approximately $200 cost of pumping is inexpensive insurance. Not only does regular maintenance save money in the long term, it also prevents your system from polluting nearby wells and waterways.
  11. How can I get more information about maintenance?
    For more information on extending the life and effectiveness of your system, contact the Worcester County Department of Environmental Programs Division at 410-632-1220.