Body of Abstract
Houses produce sewage and lawn chemicals that can contaminate ground water and ponds on Cape Cod, potentially leading to eutrophication. I measured the water quality of three ponds with different densities of houses along their shores to test the hypothesis that housing density decreases pond water quality. Specifically, I predicted that nitrogen, phosphorus, and chlorophyll levels will be the highest in the pond with the higher concentration of houses. Measurements of nitrogen, phosphorus, dissolved oxygen, chlorophyll, salinity, and temperature were made on four dates at an inlet and outlet of each pond in February and March of 2007. The number of houses within 50 m of each pond’s shoreline was counted to determine housing density. Pond water nitrogen concentrations were highest in the pond with the highest density of houses (2.5 mg/L; range for all 3 ponds: 0.8 to 2.5 mg/L). Pond water phosphorus concentrations were highest in the intermediate concentration of houses (0.041 mg/L; range: 0.025 to 0.041 mg/L). Chlorophyll was also highest in the intermediate pond (3.5 mg/L; range: 1.8 to 3.5 mg/m3). Dissolved oxygen was high in all three ponds due to cold temperatures (range: 8.5 to 9.5 mg/L). These results suggest that houses may be increasing the nitrogen levels of Falmouth ponds, but phosphorus may be a more important nutrient for stimulating eutrophication (since chlorophyll should be highest where there is more plant growth.)This study should continue into the Spring and summer, and with more ponds, to test these results.
Houses produce effluents (e.g., sewage, lawn chemicals) that can contaminate ground water and ponds on Cape Cod. To test the hypothesis that housing density decreases pond water quality, I measured the water quality of three ponds with different densities of houses along their shores.