It’s great to live on or near a lake and to enjoy all its recreational and aesthetic benefits. This proximity also brings responsibilities.

Reducing the amount of phosphorus entering the lakes is the most important step you can take for keeping the lakes healthy. Here are three steps you can take today to reduce the flow of phosphorus.

  1. Practice Lake-Friendly Lawn Care (and make sure your landscaper does too!)
  2. Pump Out Your Septic System Regularly
  3. Grow a Native Plant Buffer

Practice Lake-Friendly Lawn Care 

Don’t fertilize. The best way to reduce phosphorous is to eliminate fertilizers.  Although New York prohibits the use of fertilizers containing phosphorus unless a soil test shows it’s necessary,  fertilizers containing phosphorus are still sold, especially in nearby states.  If all other nutrients are present, as they are in our lakes, the impact of phosphorus is enormous:

a pound of phosphorous can generate 500 – 1100 pounds of algae or lake weeds.

Test soil. If your heart is set on fertilizing, have your soil tested to whether it is needed,  and if it is, how much to apply. Contact the Cornell Cooperative Extension at CCE – Westchester, 26 Legion Drive, Valhalla, NY 10595 or at 914 285-4640.  For a fee, they will send you a kit and you can send them your soil sample for a full analysis.

Use phosphate-free fertilizers. Soils in our area generally contain sufficient phosphate, so lawns generally don’t need phosphorus fertilizer. If you hire a lawn maintenance company, insist that they use a phosphate-free fertilizer.  Bags of fertilizer are labeled with three numbers, like 27-0-12. The middle number denotes the amount of phosphorus.  Never fertilize when rain is expected, never put fertilizer on frozen ground, and don’t fertilize within 10 feet of any stream, pond, lake, or other waterbody.

Use only phosphorus-free fertilizer!   Don’t treat our lakes like dirt!

Water the lawn with lake water. If you live on a lake, then use lake water to water your lawn.  It contains all the nutrients your lawn needs, and some of the water should return to the lake with the phosphorous filtered out. Don’t do this on bare soil that can erode.

Leave the leaves. Originally our lakes were surrounded by forests, and the leaves on the forest floor protected the lakes. The decomposed leaves formed humus that reduced erosion, absorbed water, and also filtered out phosphate before rain runoff reached the lakes. Development has replaced much of the forest, making the benefits that leaves provide all the more important. Where you can, leave leaves on the ground, especially on lake front property.  But don’t blow the leaves into the lakes. Use a mulching lawn mower and you may avoid raking, and the leaves will enrich your soil. 

Control weeds without chemicals.  The best form of weed control is through proper lawn care, which will give grass a competitive advantage over weeds.

Cut lawns to a length of 3 to 4 inches.  This longer length enables the grass to develop a healthier root system, which, in turn, helps the grass survive drought, disease, and insect damage. The deeper roots also do a better job of accessing nutrients.

Mow often. No more than 1/3 of the grass blade should be cut off at a time. Grass adjusts better to frequent cutting than to infrequent mowing that cuts it back more severely.

Leave the clippings on the lawn. Clippings contain valuable nutrients that feed the grass.  Frequent cutting and using a mulching lawn mower reduces the length of the clippings and they will sift down through the grass and then decay, fertilizing the soil.

Sharpen the blade on your mower. This way, the grass is cut clean. Damaged ends allow diseases to enter and also result in a more rapid loss of moisture.

Pump Out Your Septic System Regularly

Septic Systems

Routine maintenance is critical to prevent septic system failure.  Over time, sludge and scum accumulate in the tank and, if not removed, will eventually flow through to clog the drainfield.  The tank should be inspected regularly to determine the accumulation rate of scum and sludge.  Lake front owners should have their tanks pumped every one to two years.  Town law now mandates septic pumping at least every 5 years.

Proper maintenance of the septic tank will increase the life of the system. Unfortunately, all septic systems eventually fail to control phosphorus. Eventually the soils around the system are no longer able to absorb the phosphorus from septics. Even worse, if the septic fields fail, untreated effluent can flow directly into the lake.  Here are some tips to lengthen the life of your septic system.

  • Do not deposit coffee grounds, cooking fats, disposable diapers, facial tissues, cigarette butts, strong chemicals, paint, or similar materials that are difficult to decompose in your septic system.  The microorganisms that act on the materials in your septic system are the same ones that operate in your body to digest your food.  If it’s something you can’t digest, chances are the “bugs” in the septic can’t work on it either.
  • Don’t flush unwanted medications down your toilet.  Take them to the police station for no-questions-asked disposal.
  • A garbage disposal will increase the load on your septic system.  If you use one, plan to pump your septic tank twice as often.
  • Conserve water and separate times of high water use to avoid stressing your system.  The septic tank needs time to let solids settle out so that only liquids are pushed out into your septic fields.
  • Baffles are important to protect your septic system.  When your septic is pumped, have the vendor check and replace missing or failed baffles.

Our septic systems are felt to contribute more nitrates and phosphates to the lakes than any other source.  It is important to keep these systems well maintained.  If you haven’t had your septic tank pumped in the last two years, you should do so. Town Law now requires septic systems to be pumped at least every 5 years. When you have the tank pumped, have the pumping service assess the condition of your tank and its need for pumping, and inspect the input and output baffles.

Other environmentally-friendly tips include:

  • Install low flush toilets.
  • Use low flow pressure devices to reduce the volume entering your tank.
  • Use a garbage can, NOT a garbage disposal unit.  A garbage disposal typically cuts the time between pump outs in half.

Grow A Native Plant Buffer

Large areas of grass can allow rapid runoff to carry pollutants into the lakes.  Plants and shrubs along the shoreline will slow runoff and improve water quality, and they may make your lawn less attractive to geese. Trees and shrubs can also stabilize the soil and reduce erosion into the lake.  Reduce the use of fertilizers and pesticides, since these will tend to flow into the lake. A green lawn can mean a green lake, so fertilize only in the fall with non-phosphorus fertilizer.

Branches, leaves, and grass clippings should not be discarded in the lake or where runoff will carry their nutrients into the lake.

A vegetative buffer planted along the lakeshore filters out the nutrients that contribute to lake eutrophication.

A minimum buffer width of 5-10 feet is recommended. Greater buffer widths provide both increased filtration and a wildlife habitat benefit.

The easiest way to establish a buffer is to let the area along your lake shore go unmowed, and let nature take its course. A quicker method is to plant native plants with deep root systems that can capture the nutrients. Grassroots typically extend down only a few inches, so other native plants are preferable.