Water Quality Trends and Concerns

Phosphorus

Phosphorus is a naturally occurring element. All living organisms contain phosphorus and decaying organisms release phosphorus. There's phosphorus in airborne dust and in the soil under our feet. 

The Lake Sunapee watershed is generally low in phosphorus, in large part due to the underlying granite geology, minimal agriculture activity and because a sizable portion is forested. Unlike buildings and roadways, storm events are largely diffused by forested land where leaves, branches and the duff layer (shed leaves and branches on forest floor) serve to slow down, spread out and soak in rainfall.

Phosphorus can be released and washed into brooks and waterbodies due to land disturbance from development and from activities occurring on the landscape. Sources include effluent from failing septic systems, lawn & yard fertilizers, pet waste, winter sanding applications (on roads & driveways) and downstream sediment deposition caused by soil erosion. Phosphorus levels are trending upward at some locations in the watershed, in particular the nearshore or cove sites of Lakes Sunapee. If this trend continues, Lake Sunapee and other waterbodies in the region will change in character. Water clarity will decrease, aquatic plants will spread and cyanobacteria and algal blooms (which already have been occurring more often) will increase in frequency and severity.

LSPA strives to reverse this trend by encouraging residents to make personal choices that do not lead to water degradation and by supporting state and local ordinances aimed at protecting water quality. LSPA also continues to educate both youth and adult learners on watershed and water quality related topics.

To learn more about what you can do, participate in our Watershed Wise program.

Specific Conductivity

Since salt (sodium chloride) has been applied to our roads starting after World War II, conductivity levels in lakes and rivers have risen. Road salt is by far the major source of conductivity in our waters. Current in-lake conductivity has increased about 45% since LSPA began collecting water samples to analyze in the eighties.

Streams can be heavily affected - especially in summer when there is less stream flow. Less flow means less dilution - and higher concentrations of salt. Chronic high levels of salt in a stream can harm or kill fish and other aquatic life.

LSPA recognizes this is a difficult problem to address as people expect and desire roads be safe to drive on as soon as possible after a snow/ice storm. LSPA encourages towns and the state to find ways to reduce salt where possible.

What You Can Do

  • Learn more about how to reduce your impact here.

  • If you hire someone to maintain your driveway, make sure they are Green SnowPro Certified.

  • Support state and town efforts to reduce road salt applications.