Managing stormwater pollution at home
It is critical to the health of our streams that only rain goes down drains. While there are other land uses contributing towards the water quality problem in Nelson the urban community is adding a cocktail of pollutants into our streams, and ultimately the marine environment – in most cases not even realising that this is happening.
Everything that makes its way into a stormwater drain (any outside drain), is going directly into the nearest stream or the sea. This includes litter, sediment, paint and other solvents, oil, grease, dog faeces – you name it and it is probably in there.
Not only does this have an impact on stream life, it can impact on human users and ultimately, the sea and our kaimoana (seafood).
What can you do?
There are lots of things you can do, but your challenge is to choose just one thing that you may be doing, and change your actions for the better.
Around the home: If you are doing maintenance or any work around the home including concreting, waterblasting, painting, cleaning, sanding or earthworks then you must take steps to protect the waterways. Do not allow contaminated water to enter stormwater systems or streams. Always clean up waste or spilt material before it can wash into the streams but never by hosing directly into gutters.
Sweep instead of hosing: Hosing your paths and driveway to remove dirt and grime can wash it directly into the roadside gutter and eventually into streams and the sea. Silt and sediments fill the gaps among the stones in the streambed and smother habitat for insect life. Sweep the hard surfaces around your property and dispose of the sweepings into your garden or the rubbish.
Care with paintbrushes: Clean your paint brushes at an inside sink which is connected to the sewerage system, not the drain by the outside tap. Leftover paint can be allowed to dry in a container and then disposed of in the general rubbish collection. Unused acrylic or oil based paint can be taken to Resene for recycling or disposal.
Concreting: Never allow concrete wastewater to flow into stormwater drains. Any water that comes into contact with uncured concrete is highly toxic even in very small amounts. Direct all wastewater (including rain runoff) to soak into the ground or use a pump to remove and dispose of waste.
Earthworks: Make sure sediment is controlled, contained or diverted away from stormwater drains. Sediment can kill and injure fish and destroy habitats and may also contain toxic chemicals and heavy metals which can poison fish, other wildlife and stream users.
Cars: Wash your car on the lawn so that soapy water soaks into the grass instead of running into the gutter, or…. use the carwash. Never dispose of oil or other motor fluids by tipping down the drain, they need to be properly disposed of via the Transfer Station (oil and car batteries are free). Keep vehicles maintained and get leaks repaired.
Dogs: Doggy doo contains almost twice as much E.coli bacteria per gram as human faeces, seven times more than a pig and 92 times that of a cow! Please clean up after your dog when out walking. Even the deposits in the back yard can wash into stormwater drains when it rains, so pick them up too.
Litter: Can contain harmful pollutants, blocks waterways and looks horrible. Dispose of your litter in bins, via the household collection service or take to the Transfer Station. Don’t allow cigarette butts to flush into the waterways.
Garden and food waste: Garden trimmings, sweepings, lawn clippings and food waste can be composted or disposed of via the Transfer Station. Do not tip green waste over the stream bank. Dumped garden waste is one of the major causes of weed infestations along streambanks. Lawn clippings and decaying garden or food waste deplete oxygen levels in streams and can suffocate fish and other wildlife.
Garden Maintenance: Use fertilizers and sprays sparingly and do not apply over concrete. Never tip chemicals or flush out sprayers directly down the drain. Take unused, non-commercial chemicals and fertilizers to the Transfer Station.
Swimming and Spa pools: Where possible dispose of pool water into the sewerage system. It can be discharged to stormwater only if completely free from chemicals and debris. Where this cannot be done, drain onto land where it can soak into the ground, however, it must not enter into or be within 25m of waterbodies, cause ponding or affect adjoining land. Dispose of cleaning material via indoor sinks. Pool water contains chlorine which is toxic to fish and insects.