Runoff pollution and how to prevent it
What is runoff pollution?
Runoff pollution refers to the contaminants picked up by rainwater and melting snow that washes off the many impermeable surfaces found in urban environments. It is a threat to both the quantity and quality of our water supply.
As water washes over
surfaces like these:
- parking lots
…it will absorb pollutants like these:
- dirt, dust
- rubber, metal deposits
- engine oil, antifreeze
- pesticides, fertilizers, herbicides
- debris, pet waste
Unfortunately, often runoff water carries much of this pollution directly into bodies of water. It’s better when the runoff returns to the ground to infiltrate. Plants and soil will naturally filter and clean polluted runoff (to a degree).
Because of nature’s water cycle, the water we use today, and all the water that runs into the storm drain, is water that we need to use again. We share our water with everyone and with everything. It’s in our own best interests to keep it as clean as possible!
What can I do to prevent runoff pollution?
- Reduce the volume of runoff that washes into our water supply (mostly through our storm drains).
- Keep pollutants safely away from the runoff’s path.
See the section below for Watershed Friendly Landscaping Solutions that you can implement on your own property.
As a rule, only clean rain water should go into the storm drain. Here are some tips on reducing the pollutants that get into the storm water:
- Use a car wash that recycles water or wash it on the lawn with a bucket where soapy runoff will be filtered by the lawn.
- Sweep and compost grass clippings and leaves from the driveway, street, and walkway.
- Keep your car well maintained. If it is leaking oil or any other fluids, have it fixed promptly. (Did you know that 1 litre of engine oil can pollute 1,000,000 litres of fresh water?)
- Stop chlorination of pool water at least one week before emptying it, in accordance with local bylaws.
- Pick up pet waste and encourage others to do so as well.
- Keep your neighbourhood clean by picking up litter.
- Batteries, chemicals and other hazardous wastes can be disposed of at the Kingston Area Recycling Centre (KARC). For hours of operation, call 613-546-0000.
- If you see anyone emptying anything into the storm drain, you may report it to the city by calling 613-546-0000. Consider taking a picture as proof.
Do you have a leaky sewer lateral?
Your home is connected to the city’s sanitary sewer system via a pipe called a sewer lateral. Over the years these laterals can fracture or the joint seals can fail, and that allows other water sources to infiltrate into the sanitary sewer system. This otherwise clean water in the sanitary sewer is known as extraneous flow.
During times of heavy runoff, extraneous flow volumes greatly increase the risk of a sanitary sewer system overflow.
Maintaining the lateral is the property owner’s responsibility. If your home is over 40 years old or you believe that your lateral is leaky, it is recommended to have it inspected. Utilities Kingston offers lateral inspection services.
Learn more about extraneous flows.
Sump pump outlets and downspouts
It is illegal to have sump pump outlets or downspouts terminating in the sewer system. These are major contributors to sewer overflows. Citizens are encouraged to terminate them in rain barrels, artesian wells, rain gardens or onto their property where the water will be at least partially absorbed by the soil.
Learn more about sumps and sump pumps.
Learn more about downspouts.
Water-friendly landscaping solutions
Landscaping projects on your property that will slow, catch, use and/or filter rain water or snowmelt will help reduce the effects of runoff pollution. Always consider the suitability of these solutions for your landscape before implementing them. Many of these techniques will also help you use less treated water on your lawn and garden.
Here are suggestions for landscaping solutions you can do at home: wikiHow: How to Reduce Stormwater Runoff at Your Home.
Water retentive soil
Soil high in organic content retains much more water than other types of soil and is also a superb growing medium. Compost is an excellent source of soil that has high organic content. Compost is easy to make yourself with an outdoor composter, and large quantities are available at your local nursery or garden centre, as well as at KARC. If you are building a new house insist that at least a foot of high quality soil be used. Many new developments overlook this inexpensive landscape feature that can prevent flooding and provide an excellent base for gardens and lawns. Unfortunately many new developments use an inadequate amount of poor soil underneath the turf.
Terracing is used to create level soil and vertical walls as opposed to having sloped terrain. Level landscapes allow much more water to be absorbed than sloped terrains. Terraced landscapes are also aesthetically pleasing and easier to water and weed than sloped terrain.
Rain barrels or cisterns
Catching rain water with rain barrels is easy and affordable. This rain can be used to water your garden days after the rain and will reduce your water bill. A 210 litre rain barrel (like those provided in the Utilities Kingston Rain Barrel Program) will be filled by about 1 cm of rain on 18 m2 of roof. Three full barrels represent about one dollar’s worth of water. Cisterns and multiple rain barrels can be used for larger applications. Check out our Rain Barrel Program which provides a large rain barrel at a great price in the spring.
Our driveways, patios, and walkways can be major contributors to the run off pollution when they act to direct water off our properties. By installing permeable surfaces that allow the water to penetrate, you stop the runoff by absorbing it into the soil. Be sure to check out the interlocked stone parking spots on the west side of the Utilities Kingston building at 1211 John Counter Blvd. Certain types of interlocked permeable pavers can safely be plowed and have the added benefit of reducing the appearance of ice slicks during freeze and thaw cycles.
An artesian well, also known as a dry well, is simply a large hole filled with loose rock. It serves as a location where excess water can be directed so that it can be slowly absorbed into the soil.
A French drain is a drainage ditch filled with loose rock and possibly perforated piping; it serves to guide water on the property. It is an effective means of controlling erosion as well as preventing flooding by intercepting and directing water away from where it is problematic. One popular use of a French drain is below a narrow grate that runs across the end of an impervious driveway.
Rain gardens and bioswales
Rain gardens and bioswales work like a sponge soaking up rainfall and slowly using or releasing it. As gardens they are an attractive and low maintenance feature of the property. A rain garden is an area that collects rain water while a bioswale is a vegetated swale that allows water to slowly run along its length. These are excellent places to discharge sump pumps, downspouts or the overflows of rain barrels. They are also great for a low spot on your property that generates puddles after rainfall.
See also: Green Venture’s Rain Gardens
A green roof is essentially a very low-maintenance garden or lawn on your roof. Choice of plants is normally of drought tolerant plants that can subsist in a minimal amount of substrate. Green roofs have been shown to slow, filter and use rain water while providing energy efficient roofing.
Trees and shrubs
Not only do trees provide us with the oxygen we breathe but they also hold a tremendous amount of water. Their foliage slows rain fall while the roots drink up lots of water and prevent soil erosion. Most trees are drought tolerant once established. The strategic planting of trees can also provide shade, shelter from the wind and privacy.
Do you need a permit?
Before doing any landscaping adjacent to a waterway, it is important that you first check to see if a permit is required. To find out, call the City at 613-546-0000, or the Cataraqui Region Conservation Authority at 613-546-4228.