Disposal of Household Pollutants

As residents of North Cowichan, we are part of a watershed and the water cycle. It is important to deal with wastewater and household chemicals appropriately to ensure that our watershed stays healthy. In North Cowichan, we have a wastewater treatment system and a storm water system that service many residences. Stormwater drainage flows are directed into the nearest drainage basin and eventually end up in our local lakes or ocean. This storm water goes untreated and if there are contaminants in storm water runoff, they are fed directly into our watersheds.  It is all our responsibility to cut down on source pollutants before they enter our wastewater systems.

Disposal of Chlorinated Water

            Many residents in North Cowichan have swimming pools and hot tubs. There are products available locally that will neutralize the chlorine in your water making it habitable for fish and other aquatic life. Sodium thiosulphate is a chemical compound that neutralizes swimming pool and hot tub water. It is inexpensive and can be purchased at Walmart and most pool and hot tub supply stores carry it under the name of “chlorine neutralizer”. When using neutralizer, please read the label to determine how much is necessary for the size of your pool/hot tub. Once the water is neutralized, please dispose of it in one of the following two ways.

  1. Irrigation: this is the slow discharge of pool or hot tub water into the ground in your backyard after being neutralized. This is only acceptable in situations where neighboring properties are not susceptible to runoff, meaning: there are no adjacent properties that can potentially be harmed by erosion, moving water, or pooling water.
  2. Sewer system (if applicable): this is the discharge of neutralized pool water using a hose and pump at a slow flow rate that matches the drainage rate of your sink, bathtub, or sewer cleanout. It’s recommended that property owners use the sewer cleanout which is located along the sewer line of their property. The sewer cleanout is a pipe with a cap that feeds directly into the sewer system and is usually located near the house or property line. Sometimes cleanouts are located in the basement of your house.

When disposing of water from a pool or hot tub, please follow North Cowichan’s guidelines to ensure that chlorinated water does not enter our watershed untreated:

  • Please neutralize all chlorinated pool/hot tub water using a chlorine neutralizer before discharging. Bromine-based pool/hot tub water can be neutralized in the same way.
  • Make sure to neutralize the backwash water in your filter as well before discharging into your lawn, sewer cleanout, bathtub or sink.
  • Neutralized pool water can be discharged to your property through irrigation or into the sewer system through your personal sewer cleanout. If the flow is slow enough, pools can be discharged using a hose and pump through your sink or bathtub.
  • Do not discharge water into a ravine or near a steep-sloped area that would cause soil-erosion and slope instability.
  • Do not discharge pool water into a private septic system. If you are on a septic system, lawn irrigation is the best option for neutralized pool water disposal.
  • Never discharge salt water and chlorinated pools/hot tubs to the storm drain or road (treated or untreated).
  • Do not discharge neutralized pool water through irrigation onto your lawn if it can’t be properly absorbed into the ground before flowing into an adjacent property.
  • To reduce the need to dump pool water, maintain the appropriate levels of chlorine, salt, or bromine in your swimming pool throughout the season. Also, make sure your pool is covered when not in use to stop external contaminants from getting in. This will also extend the life of your pool water.
  • Please treat all expired pool chemicals as hazardous waste and return them to a CVRD waste management facility.

Cleaning Products

            Household cleaners may contain chemicals that are foreign to our wastewater treatment facilities, and if they are emptied down sinks into sewers or septic systems, they may not get properly treated before they enter the natural environment. There are affordable alternatives to mainstream household cleaners that are environmentally safe. Please look for eco-friendly household cleaners when making a purchase. If you need to dispose of harsh cleaning products, please return them to a CVRD waste management facility.

Disposal of Medications

            Prescription and non-prescription medications are constantly being flushed down the drain or the toilet. These medications cannot be completely removed from our sewage treatment facilities, and ultimately these medications end up in the ocean. Most pharmacies provide a medication return program where they will take the packaging and unused medication and dispose of it safely at no cost.


            One of the main active ingredients in laundry detergent is something called a "Surfactant". Surfactants come in many different chemical forms but their main purpose is to reduce the surface tension in water and other liquid, which helps in the cleaning process. Surfactants can be toxic to marine life, so it is very important to be careful with the amount of detergent that is used in our washing machines. North Cowichan provides residents with relatively soft water, which helps in the cleaning process and allows residents to use less detergent (normally about half the recommended amount).

Fats, Oils, and Grease

            Fats, oils, and grease are problematic with wastewater systems. They congeal and clog pipes and deplete oxygen in the marine environment. The term “fatberg” has been coined as the name for the giant build-ups of fats, oils, and grease in sewer systems that block the movement of wastewater. Fats and grease (food by-products) should not be flushed down the drain, they should be placed in your curbside collection bins with other organic waste.  Larger amounts of food based oils can be taken to a CVRD waste management facility or the Cowichan Energy Alternatives facility (beside the CVRD’s Bings Creek Waste Management Facility).


Last edited: June 7, 2022.