As part of the NH Department of Environmental Services (D.E.S.) Volunteer Lake Assessment Program (VLAP), Clough Pond Association volunteers take samples of the water in Clough Pond during the months of June, July, and August each year. Sometimes a D.E.S. biologist will accompany the Clough Pond Association volunteers to validate the volunteers' sampling procedures, to take duplicate samples for control purposes, and to generally discuss the water quality and surrounding environment of Clough Pond while the samples are being taken. 

During each sampling event five (5) phosphorus samples are taken: one (1) at the inlet, one (1) at the outlet, and three (3) from different depths at the deepest spot in the pond. Clough Pond stratifies into three (3) thermal layers each summer and samples are taken from the middle of each of those layers. The middle of those layers generally come at 2, 7, and 13 meters from the water surface. The samples are immediately refrigerated, kept in the dark and delivered to D.E.S. for analysis.  

Note: Some summers the Clough Pond Association Volunteers only managed two sampling events rather than the preferred three. In earlier years some summers were skipped entirely. Those omissions were driven primarily by costs. Phosphorus is the only test that is not offered free of charge within the VLAP program. It costs $20 to have each phosphorus sample analyzed and thus the Clough Pond Association incurs a $100 expense every time samples are taken.