Lakes & Ponds

The pond, lake, and reservoir management experience of Carr Research Laboratory, Inc. (CRL) includes diversified projects involving site inspections, field sampling, total problem evaluation, and applied research.

Examples of Representative Projects

Reclamation of Morses Pond - Wellesley, MA

This pond suffered from cyanobacterial (blue-green algae) blooms. Prior to CRL’s involvement, the algal blooms were controlled strictly by the application of copper sulfate. Over time, copper sulfate could not control the algal blooms and the lake visibility dropped below the state standard of 4 feet. Poor visibility and water quality resulted in frequent beach closings. Studies by several other consulting firms were unable to find a way to keep the beach open. CRL developed a new technique to control the cyanobacterial blooms. Potassium permanganate was introduced to remove iron, a vital micro-nutrient for cyanobacteria. During the time of CRL’s management, the pond remained open for five years with visibility averaging 11 feet. The pond never closed while under CRL’s care. CRL also wrote the proposal for obtaining a federal grant for dredging.

Reclamation of Pillings Pond - Lynnfield, MA

Pillings Pond suffered from intense algal blooms which caused an unpleasant odor. CRL was hired to assist the community in a lake study and train volunteers from the town and local schools. The study demonstrated how to effectively manage the pond without federal funds. With the assistance of CRL, the town acquired the permit to draw down the pond, utilized public education to reduce fertilizer use, and eventually located a low-cost dredging firm to remove the organic lake sediments.

Reclamation of Grainger Pond - Sherborn, MA

Grainger Pond is a 2 acre man-made pond. It suffered from years of neglect and had problems such as periphyton algal mats and occasional algal blooms. For this pond, CRL developed and implemented an innovative biological substitution program. The diverse mix of plantings included:

phytoplankton to compete against the bloom causing algae; zooplankton to consume the phytoplankton; crayfish and clams to consume aquatic weeds and the phytoplankton; aquatic plants (Chara sp.) to compete against other aquatic plants; and bass to control the frog populations which were consuming the zooplankton. Additionally, CRL instructed the pond owner how to reduce the population of unwanted geese.

CRL balanced the ecosystem so the pond could be used for recreational purposes.

Reclamation of Hinckley Pond - Medfield, MA

Hinckley Pond is a man-made public swimming pond. The pond had to be drained each year before use due to vandalism (glass, trash, etc.). As the pond refilled, algal blooms would often cause pond closings by lowering visibility to less than the state requirement. In this case, CRL developed a mix of chemical and biological management techniques. Our staff planted the pond with a diverse mix of phytoplankton, zooplankton, and aquatic plants to get the refilling pond off to a good start. Finally, potassium permanganate, copper sulfate, and alum were used to control the occasional algal bloom.

CRL’s management plan allowed for the pond to remain open to the public.

Pond Design

CRL has designed a multitude of wildlife and flood control ponds throughout Massachusetts. Many of our clients, including former MA Governor Francis Sargent, have expressed their gratitude to us for developing ponds which attract a variety of wildlife and are aesthetically pleasing.

Examples of Research Achievements

Relationship of Phytoplankton to Visibility

Visibility in water is affected by colored materials dissolved in the water, by turbidity, and by phytoplankton. CRL understands the fundamental relationship between algal biomass, as measured in Areal Standard Units per milliliter, and secchi dish visibility. We have used data collected from different lakes across New England over a period of several years to define the key relationships. Knowing these relationships, CRL can determine the relative importance of algal populations to a lake visibility problem, which assists in solving visibility problems at public recreational beaches.

Cations and Algal Bloom Potential

Some common cations (positively charged ions) are calcium, potassium, magnesium, and sodium act as micro-nutrients in natural waters. Utilizing a cation ratio analysis technique developed by Pearsall, CRL can predict the algal bloom potential for a lake. In the northern part of North America, highway salting alters the sodium concentration in the water which invalidates Pearsall’s cation ratio as a valid predictor of algal bloom potential. By using our own data from New England lakes and performing a literature search to determine the effects of sodium on algae, CRL has modified Pearsall’s cation ratio for use in areas where road salt is used so that cations accurately predict algal bloom potential. This is a useful tool in defining the value of land use control for lakes and reservoirs.

Water and Nutrient Budgets

Modeling water and nutrient budgets is a key component of developing a lake management or restoration program. CRL has researched meteorological data, lake evaporation data, wetland transpiration data, the ratios of direct storm runoff to total annual runoff, and the water quality differences between storm runoff and base flows (dry weather stream flows). By careful statistical analysis of published flow data and our own water quality data collected during various lake studies, an accurate and practical model was developed. CRL is continually refining and upgrading our models for water and nutrient budgets based on new technical literature to ensure the most reliable modeling possible to solve your lake or pond problem.

Iron Control of Cyanobacterial Blooms

Research has revealed that cyanobacterium (blue-green algae) need iron as a micro-nutrient to out-compete green algae. Dr. Carr of Carr Research Laboratory, Inc. has developed a lake treatment method using potassium permanganate to remove iron from lake waters which discourages cyanobacterial algal blooms. This technique has been successfully used for a 5 year period for the 102 acre Morses Pond in Wellesley, MA. Algal blooms which were formerly out of control after large doses of copper sulfate were eliminated or otherwise controlled.

Our proven research capability demonstrates our expertise of Limnology and assists us in the development of superior lake and pond restoration programs.