Water Quality Trends and Concerns


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

The Lake Sunapee watershed is generally low in phosphorus, in large part due to granitic geology, minimal agriculture, and a majority of forested land. But, due to development in general, septic systems, lawn fertilizers, stormwater runoff, sediment deposition and other sources, phosphorus levels have doubled in the last few decades.

If this trend continues, Lake Sunapee and other water bodies will change in character. Water clarity will decrease, algal growth and algal blooms (which already have been occurring more often) will increase in frequency and severity, and undesirable plant growth may result.

LSPA continues to fight this trend by monitoring phosphorus levels and algal blooms, and through watershed and water quality education.

Specific Conductivity

The Lake Sunapee watershed has low naturally- occurring dissolved ion content in its waters.

Ions of calcium, and carbonate, which are common in mid-western lakes, are in short supply here. A western lake or river may have conductivity levels in the range of 500 to over 10,000 microSiemens per centimeter (µS/cm). By comparison, natural stream levels in Lake Sunapee may be as low as 10 µS/cm.

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 is in the 100 µS/cm range. The trend has not been steady but levels have increased about 50-60% in the last 25 years.

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 few local streams can have and adverse impact on fish and other aquatic life.


Gloeotrichia echinulata  bloom in Herrick Cove

Gloeotrichia echinulata bloom in Herrick Cove

Cyanobacteria (formerly known as blue-green algae) are some of the oldest and widespread organisms on earth and many produce and release toxins into the water.  These toxins can be a concern for drinking water supplies and for recreational contact and are considered "unregulated contaminants".

Most cyanobacteria tend to rapidly reproduce or "bloom"  in high-nutrient (eutrophic) waters but some, such as Gloeotrichia echinulata (Gloeo), a species that has been blooming in Lake Sunapee, can bloom and form a surface scum in low-nutrient (oligotrophic) waters. 

Most cyanobacteria toxins are not released until the cell dies and the cell wall ruptures. There are several types of toxins including hepato (liver), dermo (skin), and neurotoxins (nervous system).

The World Health Organization has set a provisional drinking water standard of of 1 microgram per liter (µ/L) and 10 - 20 µ/L for recreational contact.  LSPA has the capability to assess (for advisory purposes only)  a cyanobacteria scum for approximate toxin levels for recreational contact. There have been a number of blooms and scums in local waters but, to our knowledge, toxin concentrations have not been at a level of concern.

Click here find out how you can become involved.

Click here to read the latest research.

Click here to find out what's happening at the Federal level (Environmental Protection Agency).

Contaminants of Emerging Concern (CECs)

Courtesy of Ecology Matters

Courtesy of Ecology Matters

Research is ongoing to track many chemical and microbial constituents that have not historically been considered as contaminants, but are now present in the environment on a global scale. Referred to as "emerging contaminants", they are entering our environment and our water supplies via household, commercial and industrial use.

"Emerging contaminants" can be broadly defined as any synthetic or naturally occurring chemical or any microorganism that is not commonly monitored in the environment but has the potential to enter the environment and cause known or suspected adverse ecological and (or) human health effects. In some cases, release of emerging chemical or microbial contaminants to the environment has likely occurred for a long time, but may not have been recognized until new detection methods were developed. In other cases, synthesis of new chemicals or changes in use and disposal of existing chemicals can create new sources of emerging contaminants. -United States Geological Survey (USGS) 

Many of these compounds are ingested but pass through our digestive systems into wastewater. Wastewater treatment and septic systems typically do not remove these compounds.

Courtesy of Institute for Environmental Solutions

Courtesy of Institute for Environmental Solutions

This group of "emerging contaminants" includes:

  • Pharmaceuticals, both prescription and over-the counter, including human and veterinary antibiotics, aspirin and other analgesics, caffeine, hormonal compounds, steroids, and anti-depressants.

  • Personal care products such as soap, shampoo, anti-microbials, moisturizer and sun block lotions, and fragrances.

  • Household chemicals such as stain repellants, fire retardants, pesticides, household cleansers and disinfectants.

  • Endocrine disruptors - may be found in many everyday products– including plastic bottles, metal food cans, detergents, flame retardants, food, toys, cosmetics, and pesticides.

  • Microbial and/or biological contaminants such anti-biotic resistant bacteria and cyano-bacterial toxins.

  • 1,4 - dioxane, primarily used as a solvent but is also an unintended by-product in many consumer products as a result of ethoxylation - a processing method used to reduce the effects of petroleum-based ingredients. 1,4-dioxane is a likely carcinogen and is readily soluble in water. It is found in some cosmetics, detergents, shampoos, and some pharmaceuticals.

Most of these compounds are found at trace levels but not much is known about toxicity, long-term low-level exposure, persistence in the environment, biodegradability, synergistic effects (reactions with other chemical/compounds in water or in our our bodies), or potential bio-transformations - chemical conversions mediated by living organisms.

Our ability to measure contaminants currently exceeds our understanding of their potential environmental effects (USGS).

Click here to see a recent LSPA presentation on this subject.

Learn more on how EPA and USGS are addressing and studying CECs.


Another concern is recent findings of microplastics (plastic fragments from larger plastic debris & clothing) and microbeads being found in our lakes, ponds, rivers and oceans. Microbeads are very small pellets of plastic added to some skin cleaning products and toothpaste (click here for a list). A recent study found 1900 microscopic plastic threads (captured by a filter) that were shed after washing one fleece garment.  

Albatross filled with plastic, Photo by Chris Jordan

Albatross filled with plastic, Photo by Chris Jordan

Microplastics, scientists are discovering, are harmful to wildlife as they absorb toxins found in the environment and are ingested by small filter-feeding animals. These animals are in turn eaten by larger predators and on it goes up the food web. Plastic waste in the environment isn't magically breaking down and disappearing but are degrading into ever smaller plastic bits that are turning up in unexpected places. Recent studies found microplastics in supermarket fish24 brands of beer and in table salt!


  • Avoid cosmetics and beauty products that contain microbeads (click here for a list)

  • Reduce your use of plastic products and recycle

  • Shop at farmers markets to reduce plastic food packaging

  • Wear natural fiber (plant & animal such as cotton and wool) clothing

  • Use reusable cotton bags when shopping

  • Support efforts to reduce and recycle plastics in our environment

Aquatic Invasive Species

Aquatic Invasive Species represent an ecological threat and a water quality threat.  Both terrestrial and aquatic invasive species pose ecological threats by invading areas where they are not native, competing with natives and many times eventually dominating. This species alteration in an area can lead to changes in environmental conditions such as available sunlight and nutrients, which will, in time further alter the species that are present.

Aquatic invasive plant and animal species can alter aquatic ecosystems and in the process, alter habitat and water quality.

Though the New Hampshire Department of Environmental Services (NHDES) has identified numerous aquatic invasive plant and animal species and locations throughout the state,  Lake Sunapee has had only one identified invasive plant species - variable milfoil (Myriophyllum heterophyllum), and no identified animal species.

Click here to see what LSPA is doing to prevent the spread of AIS.

Click here to see what is happening at the state level  (NHDES).

Click here to learn more about what AIS look like.