Status: 100% Complete
Project Manager: Dick Norlin (508) 865-2581
In 2003 the Town of Millbury and LSWA were awarded a $134K grant under the 319 Nonpoint Source Competitive Grants Program. Approximately $70K was awarded by the government with the remainder made up by matching labor performed by the LSWA and the Millbury and Sutton DPW staff. The objective of the project, titled Lake Singletary Storm Drain Retrofit Program, was to improve water quality through improved storm water management. According to the 1991 Diagnostic Study, direct runoff accounts for about 31% of phosphorus inputs into the lake. Prior to the storm drain improvements most storm water ran into the lake with little or no contaminant removal due to the age and technology of existing catch basins. The grant allowed us to upgrade catch basins to “best management practices” (BMP) structures. These more effectively remove the first flush pollutants and reduce nutrient and sediment loading. We will demonstrate effectiveness by periodically monitoring storm water. In order to support the 319 grant program requirements, LSWA collected storm water samples for total suspended solids (TSS) and total phosphorus (TP). The samples were collected and analyzed pre and post storm drain improvements.
TSS is a measure of the sediment that is present in a water sample. TSS contributes to turbidity and reduced water clarity.
TP is a measure of nutrient content and acts as “fertilizer”, encouraging weed and algae growth.Both of these contaminants are elevated during storm events, during which time sediments and nutrients present in the watershed can be carried into the lake with runoff. This type of contamination is called non-point source pollution, because the source is spread over a large area. Reduction in phosphorus and sediment loading was accomplished (see below)by upgrading existing storm drain structures with storm water BMP (Best Management Practices) structures. The project was completed in 2006.
Significant improvement detected for suspended solids removal at site six.
No significant improvement detected for phosphorus removal - need more data.