DUFRESNE GROUP SELECTED FOR DARTMOUTH COLLEGE STORMWATER SYSTEM EVALUATION
Dufresne Group is proud to announce that they have been selected to complete an evaluation of the expansive storm drain system at Dartmouth College in Hanover, New Hampshire to identify hydraulic, structural and water quality deficiences. The project includes the development of a computerized hydraulic modeling of the existing storm drain network, water quality sampling and analysis, closed-circuit television (TV) inspection of all mains, and the development of 5-year and 10-year improvement plans for the storm water system.
Dufresne Group will utilize the software program StormNET to develop the hydraulic model which will include the approximately 1,000 existing catch basins and drain manholes and all connecting storm drain pipes. The model will be used to evaluate pollutant levels, infiltration rates, and to evaluate various water quality and quantity controls as a means to alleviate system deficiencies. In addition, the computer hydraulic model can be used to estimate the effects of future campus development and system modifications and upgrades.
The water quality sampling will consist of collecting samples at 10 locations which will be analyzed for suspended solids, Escherichia coli, fecal coliform, total phosphorus, nitrate, conductivity and pH based on land uses and the receiving waters apparent quality and impairments. DG will record depths of flow in conjunction with water quality sampling for comparison with model predictions and assist with evaluating water quality impacts from the College on the receiving water bodies.
Dufresne Group is teaming with Comprehensive Environmental, Inc. (CEI) for the stormwater model development. CEI developed the New Hampshire Stormwater Management Manual and will provide valuable recommendations for best management practices that can be implemented on the college campus.
The television inspections are underway, being performed by Stearns Septic Service, Inc. utilizing a motorized robotic camera to document the internal characteristic of the storm drain mains and identify deficiencies. Below are three examples of deficiencies discovered during the TV inspections.