Preliminary analyses and discussion at these meetings suggest that loading approximations using various methods, including criteria from DEP, CCC, and BBP models, result in acceptable ranges, but recent research claims of extensive denitrification in the Cape Cod aquifer require further assessment. Development of GIS parcel coverage information is necessary for subsequent wastewater facilities planning assessments for areas that are identified as having excessive nitrogen loads. Flushing studies of coastal embayments are also a key for developing water quality protection options. Comparing nitrogen loads to local residence time calculations can produce estimates of average expected nitrogen concentrations and reasonable assessment of general ecosystem conditions. Water quality data can later be incorporated into appropriate flushing study models to accurately predict nitrogen concentrations throughout a coastal embayment and refine the assessment of ecosystem conditions and potential management options.
Critical attention needs to be focussed on the development of appropriate nitrogen loading limits.
The assessment of nitrogen loads to and water movements within an embayment are adequate at this point for regulatory and planning decisions, but definition of the appropriate nitrogen limit requires additional attention. The Commission suggests that this data should be reviewed, and considered with the available nitrogen loading information, to provide more refined nitrogen loading standards for coastal embayments. Additional review of this data also should be able to help refine the predictive ability of nitrogen loading and coastal flushing models. In addition, discussions should also focus on ways to limit impacts from future development within these watersheds, since additional development will further stress these ecosystems. Town Boards of Health currently have the authority under Title 5 to assist in the protection of coastal embayments by designating embayments as nitrogen sensitive.