Stormwater Management

Stormwater is produced every time rain or snow is not absorbed directly into the soil. Stormwater can pick up oils, litter, sediments, fertilizers, pesticides, herbicides, and pathogens as it travels across roads, buildings, dumpsters, lawns, and parking lots. If this stormwater flows into lakes and streams it can be a major source of water pollution. It is estimated that 70 percent of the water pollution in the United States comes from stormwater and other indirect discharges that are collectively called "nonpoint" sources.

In 1972, the Federal Clean Water Act (CWA) was adopted to improve the quality of our Nation’s waters. The Act sought to accomplish this by minimizing and eliminating what are commonly referred to as "point sources" of pollution, sources of pollution that originate from a pipe or other specific point of discharge. There significant improvements in water quality, water pollution remained a problem in waterbodies.

The Clean Water Act was amended in 1987 to target the non-point sources of pollution. Under Phase I of this effort, which began in 1990, municipalities having a population greater than 100,000 people were required to implement programs and projects that would reduce non-point pollution. In 2003 this requirement was extended to almost all other municipalities including the Town of North Castle under what is commonly referred to as "Phase II".

In New York, Phase II requires that all regulated municipalities obtain a permit from the New York State Department of Environmental Conservation for the discharge of stormwater runoff into their surface waters. As a condition of this permit, regulated municipalities must develop and implement a comprehensive stormwater management program that includes mandated programs and practices in the following six categories:

  • Public education and outreach on stormwater impacts
  • Public participation/involvement
  • Illicit discharge detection and elimination
  • Construction site stormwater runoff control
  • Post-construction stormwater management in new
  • Development/redevelopment
  • Pollution prevention/good housekeeping for municipal operations

Our Plan

The Town of North Castle has filed a Stormwater Management Plan with the New York State Department of Environmental Conservation that describes what the Town will be doing each year to meet the requirements the requirements of the Phase II stormwater management. The document can be viewed here.

Town of North Castle Stormwater Management Program Annual Report

One of the requirements of the SPDES General Permit for Stormwater Discharges from Small Municipal Separate Storm Sewers (MS4s), is the preparation of report describes pollutants of concern and their sources, steps being taken to reduce pollutants in stormwater runoff and of pollution prevention practices.

The Town is required to prepare an annual report that describes how its programs address the impacts of stormwater discharges upon waterbodies, the pollutants of concern and their sources, steps being taken to reduce pollutants in stormwater runoff, and the effectiveness of best management practices. The Town is required to make the report available to the public and to provide the public with an opportunity to comment on the Town ’s program at a public hearing prior to it being filed with the New York State Department of Environmental Conservation.

This year's report can be found above.

Previous Reports can be viewed below:

What Can I Do?

Your day-to-day activities on land have an effect on your water quality, whether it’s your drinking water or your favorite beach, but there are simple things that you can do differently in order to protect this valuable, natural resource.

  • Start by familiarizing yourself with the water cycle.
  • Then identify the watershed you live in so that you understand which water bodies are affected by your land use activities.
  • Build a rain garden on your property.
  • Explore the individual land use activities on the right drop down menu.

Winter De-Icing

Road salt is the most common deicer used to promote safe motor vehicle travel during winter months. The most commonly used road salt is sodium chloride, which is readily available, inexpensive and effectively melts snow and ice.  However, after more than half a century of widespread use of road salt in North America, environmental and scientific communities have begun to notice the impacts of road salts on water quality, soils, vegetation and wildlife. 

The Town of North Castle Highway Department, recognizing the potential impacts associated with salt application has been a leader in deploying a pre-emptive salt brine application.  Salt brine is 77% water and 23% salt and is applied prior to a storm and can reduce the amount of salt necessary to clear the roadway by 2/3 as compared to a straight application of rock salt.

  • Water Quality:
    Chloride concentrations have increased in our local reservoirs due to increased use of road salt. This has an effect on its taste and an impact on human health.
  • Soils:
    Exposure to salt may kill some healthy soil bacteria, thereby prompting potential changes to soil structure, altering microbial animal populations, and impacting the plants that depend on both the bacteria and microbial animals.
  • Vegetation:
    Elevated levels of sodium and chloride in the soil inhibit water and nutrient absorption which leads to long-term growth inhibition and direct toxicity to plant cells.
  • Wildlife:
    Damage to vegetation degrades wildlife habitat by destroying food resources, shelter, and breeding or nesting sites.  Road salt can have direct toxic effects on the birds and mammals that drink snowmelt or eat road salt, and it can attract white-tailed deer thereby contributing to potential collision with motor vehicles.

Given the environmental impacts, salt is still a necessary and generally accepted part of the winter environment. It provides safety and essential mobility for motorists, commercial vehicles and police, fire and other emergency vehicles.  In fact, if responsible agencies fail to keep their roadways clear of ice and snow, they can be sued. Learn more about salt from the Salt Institute.

While municipalities are legally responsible for providing passable and reasonably safe roads, they cannot always produce bare pavement directly after a snowstorm; therefore, we need to work together in order to understand the connection safe winter driving, salt usage and water quality.

To address these issues, the Northern Westchester Watershed Committee has created a Highway Deicing Task Force whose mission is to provide for the safety and welfare of the traveling public while protecting natural resources through best management practices.  Read the November 2007 Highway Deicing Task Force Report It is noted that Town of North Castle Highway General Foreman Craig Useted was a member of the Task Force.  The Town of North Castle has adopted all of the recommendations contained in the Task Force report.

Driving Tips:

  • Check the forecast
    When you see an extreme forecast, plan ahead. Talk to your employer, local school or daycare center. Check road reports, forecasts and roadway temperatures at the New York State Department of Transportation Winter Travel Advisory.
  • Limit travel
    During heavy snow storms, residents should stay off the roads. Plowing becomes more difficult when there is traffic on the road. If residents must travel, they should make every effort to use major thoroughfares that have been plowed and/or treated with salt.
  • Before leaving home: prepare yourself and your vehicle 
    Emergency groups encourage you to have supplies that will last three days. You should keep your vehicle in top operating condition all year round for safety and fuel economy. Read your owner's manual and we encourage you to read and print Winter Driving Tips.
  • Take it slow!
    You cannot drive at normal highway speeds during a winter storm event.  SUVs are not any safer in snow than other car although people drive them as if they are.

Snow Maintenance Tips:

  • Park in driveway
    Your car should be parked in your driveway so that the plow has access to your street and can the road.
  • Salt before the snow
    A little salt will keep snow and ice from bonding to the pavement by salting before snow has accumulated.  Salt should not be used to melt every bit of snow and ice. Use only enough to break the ice/pavement bond, and then remove the remaining slush by plowing or shoveling.
  • Shovel to the right
    When clearing the end of the driveway, place snow to the right to prevent it from being plowed back into the driveway.
  • Shovel away from roadway
    Do not pile snow in areas that will block or obscure a driver's view of the roadway and oncoming vehicles.  This causes a dangerous situation for motorists who are driving on a plowed road and unknowingly hit blocks of snow placed out in the road.

Property Maintenance

When you dump a can of paint thinner down the drain or throw out an old car battery with the trash, the impact on your water resources could be disastrous. The average household contains between three and ten gallons of materials that are hazardous to human health or to the natural environment. Collectively, these materials can poison our water if they are not stored carefully and disposed of properly.

What is a hazardous material?

The United States Environmental Protection Agency considers a substance hazardous if it:

  • Can catch on fire
  • Can react or explode when mixed with other substances
  • Is corrosive
  • Is toxic
Dangers of hazardous waste

The improper disposal of household hazardous wastes can cause problems for the entire community. Wastes can be explosive, highly flammable, or corrosive. For example, the acid from discarded auto batteries can eat away many substances. Some wastes are poisonous to humans or wildlife, while others can cause cancer, birth defects or other serious medical problems.

Where do we put them?

One of the worst ways to dispose of many hazardous materials is to “just dump them down the drain.” Wastewater treatment plants are not designed to handle certain types of hazardous wastes. Unfortunately, disposing of wastes in a landfill has not proven an effective solution either. Without special design, the modern sanitary landfill is not equipped to accept hazardous wastes. Hazardous wastes improperly disposed of in a landfill can pollute the environment through the groundwater, surface water and air.

A quick word on Phosphorus

Phosphorus is a nutrient essential for plant growth. It is found in lawn fertilizers, some detergents, and human and other animal waste. Too much phosphorus in water causes algal blooms and excessive aquatic plant growth. These plants, and the water quality problems that occur when they decompose, can harm fish and other organisms and limit our use and enjoyment of local lakes. While phosphate is banned in laundry soaps and hand dishwashing detergent, it is still used in automatic dishwasher detergents.

Please help keep phosphorus out of our water bodies by using phosphorus-free or low phosphorus detergents for your dishwasher. (Phosphate is the form of phosphorus found in detergents.)

What can you do?

Reduce the amount:

  • Before you buy a product, read the label and make sure that it will do what you want
  • Do not buy more than you need so that you will not need to dispose of the surplus
  • Read and follow directions on how to use a product and dispose of the container
  • Use safer substitutes when available.
  • Try out one of our recommended alternative cleaners or homemade recipes for non-toxic alternatives listed below.
Dispose of the wastes properly

Car Maintenance

Many of us believe we save money by washing our own cars and changing the oil ourselves. But do we really? Have you ever calculated the number of gallons of water you use and estimated how much it costs? You'd be surprised that you may not be saving all that much. And, on top of it, you're adversely affecting the surrounding environment and adding to the cost of potential environmental clean-ups.

Car Washing

Most citizens are not aware that by washing the grime off their vehicles, they are polluting the environment. When cars are washed on streets and driveways, dirty water enters storm drains and eventually winds up in rivers, streams, creeks and lakes.

Car detritus, along with detergent-rich water used to wash the grime off cars, has been characterized as one of the major nonpoint sources of heavy metals, oil and grease, and other components, such as rubber.

Collectively, car washing activity adds up to big problems for our local lakes, creeks and streams. Dirty water containing soap, detergents, residue from exhaust fumes, gasoline, heavy metals from rust and motor oils can wash off cars and flow directly to storm drains and into the nearest creek or stream where it can harm water quality and wildlife.

Washing your car is only a problem if you don’t know where or how to do it correctly.

What can you do?

The best way to minimize the effect washing your car has on the environment is to use a commercial car wash. The average homeowner uses 116 gallons of water to wash a car, while most commercial car washes use 60 percent less water for the entire process than a homeowner uses just to rinse the car.  And, most locations reuse wash water several times before sending it to a treatment plant.

However, if you choose to wash your car at home or on the street, here's what you can do to minimize the water quality impact:

  • Use only biodegradable, phosphate-free, water-based cleaners.
  • Use a high-pressure, low-volume hose with a trigger nozzle to save water.
  • Wash on an area that absorbs water, such as gravel, or grass, which filters water before it enters groundwater, storm drains or creeks.
  • Avoid washing cars on concrete or asphalt pavement.
  • When planning a car wash fundraiser, try developing a partnership with a commercial car wash facility or have the cars washed on a permeable surface.
  • Always empty wash buckets into sinks or toilets.
Car Oil

Never dump motor oil, antifreeze, transmission fluid or other engine fluids down storm drains, into road gutters, on the ground or into a ditch.

When oil leaks from our cars onto driveways, streets and parking lots, there’s a good chance it will be washed into nearby storm drains, eventually making its way into our streams, ponds, reservoirs and estuaries. Picture the number of cars in your area and imagine the amount of oil that finds its way from leaky gaskets into our water bodies.

Used oil from a single oil change can pollute up to one million gallons of freshwater. Improper disposal of used oil, which includes oil leaking from cars, contributes significantly to stormwater pollution. The EPA estimates that American households generate 193 million gallons of used oil every year and improperly dump the equivalent of 17 Exxon Valdez oil spills every year.

What can you do?
  • Check your car often for oil and fluid drips and other leaks and fix them promptly.
  • Have your car regularly tuned-up to reduce oil use.
  • Use ground cloths or drip pans under your vehicle it you have leaks or are doing engine work.
  • RECYCLE used motor oil. Many auto supply stores, car-care centers, gas stations, and some public works facilities, accept used motor oil.
  • Clean up spills immediately. Use kitty litter or sand to soak up the liquid. Properly dispose of this material after the spill.
  • Collect all used motor oil in containers with tight-fitting lids. Do not mix waste oil with gasoline, solvents or other engine fluids. This contaminates the oil, which may otherwise be reused and may form a more hazardous chemical.

Septic Systems

Leaking and poorly maintained septic systems release nutrients, bacteria and viruses that can be picked up by stormwater and released into nearby waterbodies.  Septic systems can be a source of Phosphorus

How well does your septic system work?

Septic systems are found in the majority of homes in Armonk and the Eastern District, while municipal sewers are found in North White Plains.  Properly designed, installed, and maintained septic systems have little adverse effect on the environment. As a homeowner, you have a major influence on how well your septic system works.

What you can do

Maintenance is the single most important consideration in making sure a septic system will work well over a long period of time. Too often homeowners forget that whatever goes down the drain or toilet ultimately either finds its way into the soil or remains in the septic tank until it is pumped out. Use common sense and you should have few problems with your septic system. 

The following maintenance practices will keep your system running smoothly:

  • Know the location of all components of your septic system; keep heavy vehicles away from the system.
  • Don’t plant trees or shrubs near drain tiles since their roots can clog drain lines.
  • Dispose of household chemicals properly. Do not pour them down the toilet or drain. They can destroy the bacteria of the septic tank.
  • Distribute your laundry chores throughout the week to avoid overloading the system on any given day.
  • Don’t use garbage disposals. They contribute unnecessary solids and grease to your septic system.
  • Conserve water whenever and wherever possible.
  • Don’t use toilets as trash cans.
  • Plant only grass over your tank and fields.
  • Monitor your septic tank yearly and have a reputable contractor remove sludge and scum every 3 to 5 years. This helps ensure that there is enough space in the tank for waste-water, and prevents solids from escaping into the absorption system.
How septic systems function

Septic systems have two key components – a septic tank and a soil absorption system. The septic tank is a container that receives wastewater from your bathroom, kitchen, and laundry room, allowing the heavy solid particles to settle and light materials to float to the surface of the tank. These materials become sludge and scum. Bacteria in the wastewater feed on the sludge and liquefy the waste products.

This process requires time. To permit enough time for settling and floatation, regulations require that septic tanks be sized according to the expected daily flow and waste water from your home.

The soil absorption system (drainfield) consists of a distribution box, perforated distribution lines made of tile, and an area of soil. The soil absorption system receives wastewater from the septic tank and removes harmful, disease-causing micro-organisms, organics and nutrients. For this part of the system to function properly, it must be constructed carefully on suitable soil.

The soil needs time to filter out these harmful materials from the wastewater. Sand is not a suitable soil because it allows wastewater to pass through too fast and clay accepts only small amounts of wastewater. State and local regulations that determine what constitutes suitable soil have been developed after careful consideration of many factors that affect a soil’s ability to adequately treat domestic waste-water.

Health Issues

The threat of disease is a key problem with treating human wastewater. The epidemics that killed millions of people in the Middle Ages were caused by mixing of human waste with drinking water supplies. Domestic wastewater contains bacteria and viruses that cause dysentery, hepatitis, and typhoid fever. To protect your health, it’s important to exclude these organisms from both surface and groundwater. That is why sewage treatment plants use chlorine and other biocides (substances destructive to many organisms). Fortunately, soil and soil bacteria can effectively remove pathogenic (disease-causing) microorganisms from wastewater treated in a properly functioning septic system.
Nutrients such as nitrogen and phosphorus, contained in domestic wastewater, can cause both health and nuisance problems if allowed to reach surface or groundwater supplies. Nitrogen in its nitrate form poses the most significant threat to our health. When ingested by infants, nitrate can interfere with the blood’s ability to carry oxygen, causing “blue baby” syndrome. Nitrogen carried in septic tank wastewater is usually in the form of ammonia. This ammonia is readily transformed into nitrate, which can easily become part of ground and surface water supplies.

Nutrients also fuel the growth of algae and are responsible for the subsequent loss of oxygen, causing serious problems for our local waterbodies.

The Westchester County Department of Health provides more information on septic system maintenance and has lists of licensed septic contractors, professional engineers and registered architects.

Lawn Care

There are phosphorous concerns with grass clippings and leaves.

The most effective lawn care programs begin with a clear understanding of what grass really needs in order to grow. Here are the most important things you can do for your lawn:

  • Aerate Your Lawn.  Tightly packed soil restricts root growth and prevents water and fertilizer from penetrating the soil (increasing stormwater problems). Core aerators remove plugs of soil throughout the lawn. Holes give grass roots space to grow and helps prevent weed growth and thatch problems.
  • Mow High/Leave Clips.  Be sure your mower is set to three inches. Tall grass helps to conserve moisture and promotes root growth and shades out weeds.  Sharpen your mower blade at least once a year. Let short clippings fall back into the lawn; they do not contribute to a build-up of a thatch layer. Clippings are a source of nitrogen, so fertilizer can be reduced by 25% or more.
  • Water the Lawn to Minimize Disease and Insect Pests.  A green lawn in Westchester County needs 1/2 to 1 1/2 inches of water per week, depending on the site and turf grass type. Over watering causes more weed, disease and pest problems than under watering. Install rain gauges and measure how much you are watering.
  • Water early in the morning.  Water applied in the afternoon evaporates too quickly, and watering in the evening can encourage disease problems.
  • Maintain fertile soil.  Test your soil every three to four years to determine the amount of fertilizer your lawn needs. Do not over fertilize. The excess can damage the lawn and may feed lake weeds instead of your grass.
  • Leaves, Grass Clippings and Other Yard Waste.  Leaves, grass clippings and other yard wastes should not be left on paved areas where they can wash into storm sewers and into our lakes or streams. As these wastes decompose, they become fertilizer, encouraging aquatic weed and algae growth. They can be composted, tilled into the garden, or collected and put out for special pick-up. Contact your local public works department for pick-up dates.

Lawns and many garden plants do not need as much fertilizer as you might think, especially if you use certain grasses and native plants. Excess fertilizer applied to lawns and gardens wash off and pollute streams. Because they contain nutrients such as nitrogen, phosphorus and potassium applied in excess, these nutrients nourish weed growth and algae in our lakes, rivers and steams.

Fertilizer advice:

  • Have your soil tested every three to four years. To avoid over fertilizing your lawn, obtain a free soil test so you can determine exactly how much and what kind of fertilizer you need. Follow package directions and apply only the amount needed. Remember to exclude the land area covered by your home and garden when calculating the square footage of lawn you need to cover.
  • Choose a dry, calm day for the application.  To reduce fertilizer runoff into waterways, don’t fertilize just before a forecasted rain storm, do not apply fertilizer over paved areas and avoid applying on windy days.
  • Fertilize in the fall.  September is best for lawns, with a repeat application in spring (May) if needed. Water soon after applying fertilizer to promote fast absorption into the plants.
  • Store unused fertilizer. Unused fertilizer can be stored in a dry place or given to someone who will use it up. Storing unused fertilizer for later use or sharing it is preferable to disposing of unused amounts.

In recent years, there has been a significant increase in the use of chemical pesticides by homeowners (and their landscapers) in their quest for an aesthetically perfect lawn. At the same time, a growing body of science links exposure to lawn pesticides with a myriad of human illnesses. Westchester County has been one of the more progressive counties in New York State when it comes to the issue of pesticides.

  • 1996 – Westchester County Pest Management Committee established.
  • 2001 – County Board of Legislators adopts the Neighborhood Notification Law.
  • 2004 – Grassroots Healthy Lawn Program introduced.

If you use pesticides, please remember the following:

  • Determine if you have a pest problem that is significant enough to need control, before you purchase a pesticide.  Many pesticides do not solve the problem, they just lesson the symptoms. Most pesticides are not intended for preventative use. Read the label carefully to be sure the product is intended for your particular pest problem. Choose the least toxic product available, buy only the amount you need and apply the smallest amount needed to do the job.
  • Read and follow label directions exactly.  In general, pesticides should be applied only on calm, dry days when no rain is forecast for at least 24 hours. Wind and water can carry pesticides into sewers and waterways. Do not apply pesticides over sidewalks, gutters, or other paved areas, where they can easily wash into sewers or waterways.
  • Try not to purchase more than you will need in one year. Most pesticides have a short shelf life (e.g. 2 years). If you have leftover pesticides that you can no longer use, give them to someone who can use them up or store them in the original container. Contact your local public works department for disposal options.

Constuction Sites.

Construction sites are also a source of phosphorus.

Detergent Use

There are phosphorus conerns with detergent use.

Additional Information

The Town of North Castle Conservation Board has prepared information on subjects relating to preserving our surface water and groundwater:

Links of Interest

There are many websites that provide information on the stormwater management. Below are several that are particularly useful:

New York State Websites
United States Environmental Protection Agency
Other sources of information on stormwater management

For More Information:

If you want more information on the Town’s stormwater management program or what you can do to reduce the impacts of stormwater, contact:

Town of North Castle 
Planning Department 
17 Bedford Road

Armonk, New York 10504 
(914) 273-3000 x43

What North Castle is Doing

Pursuant to § 173-9 of the Town Code, illicit discharge is illegal and punishable by fines up to $1,000. The Town has developed procedures to find, stop and eliminate all illicit discharges encountered. A hotline (914-273-3323) is available to any citizen who observes and wishes to report an illicit discharge.