The Maryland Department of Environment (MDE) finalized regulations that will require almost all new construction and many property renovations to use enhanced nitrogen removal septic systems (BAT systems). The regulation, which MAR and a number of groups opposed, requires that Best Available Technology (BAT) systems be used for the following properties:
- All new construction in either the Chesapeake Bay or Coastal Bays Watershed
- New construction in any watershed of a nitrogen-impaired body of water
- Replacement systems for existing property located in the Critical Areas of the Chesapeake Bay or Coastal Bays Watershed
Existing property in the Critical Areas (item 3) were already required to use BAT systems, but the requirements in items 1 and 2 are new and would affect most new construction throughout the entire state of Maryland.
Additionally, MDE defines new construction as building renovations that require expansion of the current septic system capacity.
Finally, all new BAT systems will be required to follow prescribed maintenance and operation procedures. This could mean that owners will be required to obtain mandated operational permits, annual service contracts or other measures required by local government.
MAR opposed these regulations because of concern over the extreme cost of BAT systems -- many cost $8-12,000 on top of the cost of a conventional system. Moreover, if a property has limited space to locate new drain fields, the required systems can cost twice that amount.