have permit requirements to verbally report unauthorized discharges and other permit violations to the DEP upon knowledge of the incident(s).
DMR also conducts periodic evaluations of POTWs in areas where shellfish growing areas are conditionally managed based on POTW performance. A Memorandum of Agreement requires that POTWs report sewage over- flows or disinfection problems to DMR.
Are there any overboard discharge systems?
An overboard discharge system (OBD) is a discharge of treated (via sand filter or mechanical aeration) wastewater from a residential, commercial, or public facility to a stream, river, or the ocean. OBDs have been regulated by the Maine DEP since the 1970s, when the Clean Water Act banned direct discharges of untreated waste (straight pipes). OBD treatment systems were installed for those facilities that were unable to connect to POTWs or unable to install a sep- tic system because of poor soil conditions or small lot sizes. Approximately 1,390 licensed OBDs remain throughout the state today, less than half the number of OBDs documented to be in existence in 1987. Use of an OBD requires a license from the Maine DEP. A site evaluation is required for a license to be renewed or when a property is transferred. If there is a practical non-discharging alternative, the OBD may have to be eliminated. OBD systems are periodically inspected by DEP staff to determine if they are being prop- erly maintained and operated. Failure to meet the condi- tions of a waste discharge license subjects the violator to possible enforcement action.
When OBDs are improperly maintained or malfunction, they can discharge harmful bacteria into surface waters. Several shellfish growing areas in Maine are closed due to the actual or potential threat of contamination by OBDs.
Determine the location and status of OBD systems along the shoreline and within the watershed of concern. Record properties with OBDs and the corresponding OBD waste discharge license number on the field datasheets for transfer into the sanitary survey database. Specific information on each system can be obtained from the DEP, including inspection/ compliance history reports, maps indicating the location of each OBD system and, when available,
Conducting the Sanitary Survey
plans for removal. The DEP maintains a GIS layer that includes the geographic coordinates and links to descriptive information about all of the licensed OBD systems. OBDs may require additional follow-up depending on documented issues and/or bacteria sample results indicating a problem with the system. This may require additional DEP inspections and working with the owner(s) to take corrective actions.
The presence of an OBD mandates a shellfish harvesting closure of an area within 300 feet from the outfall pipe. However, to facilitate administration of closed areas, obvi- ous landmarks and straight lines are used to delineate closed areas so that harvesters and wardens will be able to easily determine whether they are within or outside of a closed area, which means the actual closure may be much larger than the potentially polluted area. Stretches of shore- line with multiple OBDs will create larger closed areas.
DEP provides grants to remove some OBDs. To qualify, the OBD must be legally licensed by the DEP, and OBDs affecting shellfish growing areas are given higher funding priority.54
Which properties are served by subsurface wastewater disposal (septic) systems?
Improperly maintained or poorly sited subsurface waste- water disposal systems will likely malfunction and cre- ate conditions that can threaten human health and the environment. Often, little thought is given to septic system inspection and maintenance until the system malfunctions. Untreated effluent or “breakout” from a malfunctioning sys- tem can be obvious by sight or smell or by the backing up of sewage into the structure. However, malfunctions can also be difficult to detect. Effluent can percolate through soil and ledge into ground and surface waters, and be carried by stormwater runoff to adjacent water bodies.
In Maine, depending upon the capacity of the system, subsurface wastewater disposal systems are designed by either a licensed site evaluator or engineer, with a permit and construction inspection completed by the local plumbing inspector (LPI). If problems with a system are suspected, an inspection may be appropriate to ensure that the system is properly functioning and that it was constructed in accordance with the Maine Subsurface