Lead Agency: University of New Hampshire Stormwater Center
Primary Contact: James Houle
Project Partner(s): NH GRANIT, UNH Earth Systems Research Center, Horsley Witten Group
Sponsor(s): NH Department of Environmental Services
Start Date - End Date 09/01/2019 - 05/01/2020
Description: In an effort to better understand the contributing factors to the declining water quality in the Great Bay estuary and its tributaries, an analysis of pollutants from the surrounding land area was conducted. The study focused on 36 (the number of communities for which digital tax parcel data were available) of the 42 communities within New Hampshire's coastal watershed: Barrington, Brentwood, Chester, Danville, Deerfield, Dover, Durham, Epping, Exeter, Farmington, Fremont, Greenland, Hampton, Hampton Falls, Kensington, Kingston, Lee, Madbury, Middleton, New Castle, New Durham, Newfields, Newmarket, Northwood, Nottingham, Portsmouth, Raymond, Rochester, Rollinsford, Rye, Sandown, Seabrook, Somersworth, Strafford, Stratham, and Wakefield.
The tax parcel data were combined with impervious surface data, land use data, soil data, conservation lands data, and pollutant load export rate (PLER) data and analyses were performed in order to determine the pollutant load by parcel for 3 primary contributing pollutants: nitrogen, phosphorus, and sediments. The resulting data were then exported to community-based summaries and 3 map products were generated for each community (total nitrogen, total phosphorous, and total sediments). The maps and town summary sheets can be viewed/downloaded here: