Environmental health hazards can affect the air we breathe, the water we drink, and the spaces we live and work in. These hazards may include biological, chemical, and physical risks that can lead to illness, injury, or long-term health problems if not addressed properly.
GEPH’s Environmental Health team monitors and responds to a variety of health hazards across our region. We work closely with local and provincial partners to assess risks and provide guidance to protect public health.
Safe Drinking Water
Safe drinking water is essential for your health. In Ontario, municipal water systems are closely regulated by the Ministry of the Environment, Conservation and Parks to ensure water quality and safety.
If you get your drinking water from a private well, you are responsible for making sure it is safe to drink. Grand Erie Public Health (GEPH) offers free well water testing for all residents.
Why test your well water?
Well water can look, taste, and smell fine, but still contain harmful bacteria. Testing is the only way to know if it’s safe.
We test for two types of bacteria:
- Total coliforms: Common in soil, vegetation, animal waste, and sewage. If found in your water, it means surface water may be entering your well.
- E. coli: Found in the intestines of people and animals. Its presence usually means sewage contamination from a nearby source.
These bacteria can cause illness such as diarrhea, stomach cramps, and other health concerns.
When to test your well water:
- At least three times a year (spring, summer, fall)
- After any well repairs
- After flooding
- If your well has been unused for several weeks
- Any time you notice a change in taste, smell, or colour
Each test is a snapshot of your water quality. The more often you test, the more confident you can be in the safety of your drinking water. In addition to testing, inspect your well once a year to make sure it is in good condition and free from damage.
Note: We do not test for chemicals like sodium, nitrates, or lead. Contact a private lab for chemical testing. Private labs information can be found here: List of Licensed Laboratories — Ontario
The laboratory will only accept samples collected in the official testing bottle. Always collect from an indoor drinking water tap (kitchen or bathroom):
- Wash your hands.
- Remove any faucet attachments (screens, aerators, etc.).
- Clean the faucet with an alcohol swab or diluted bleach solution (1 part bleach to 10 parts water).
- Run cold water for 5 minutes.
- Open the sample bottle only when ready to fill. Do not rinse it out.
- Fill water to the 200 mL line and recap immediately.
- Label the bottle and complete the form provided.
- Keep the sample cold (use a cooler with ice packs in warm weather).
- Deliver to a drop-off location within 24 hours.
Detailed instructions are included with the bottle and available on the Public Health Ontario website.
Filling out the form:
Be sure to complete all required fields (*). Incomplete forms will not be processed.
You’ll need to include:
- First and last name*
- Mailing address*
- Well location (911 address or description)*
- Date and time of collection*
- Public Health Unit number*
- Daytime phone number*
- Whether you use a purification system
- How you’d like to receive results (by mail or pick-up)
Keep the barcode sticker for your records. You’ll need it if you call for results.
For online water sample submissions, click here.
Testing bottles can be picked up at GEPH, Monday to Friday, 8:30 a.m. to 4:30 p.m. (except on holidays).
| GEPH Locations | Address | Drop Off Hours |
| Brantford | 194 Terrace Hill St. | Monday to Thursday 8:30 a.m. to 4:30 p.m. |
| Simcoe | 185 Robinson St. (Suite 200) | Monday to Thursday 8:30 a.m. to 4:30 p.m. |
| Caledonia | 100 Haddington St. | Monday to Thursday 8:30 a.m. to 4:30 p.m. |
| Dunnville | 117 Forest St. | Monday to Thursday 8:30 a.m. to 4:30 p.m. |
Please do not drop off water samples to the Health Unit on Fridays or on holidays when we're closed.
Burford County of Brant Office drop off is the Last Wednesday of every month (except December) from 8:30 am to 2 p.m.
You may also pick up testing bottles at the following locations across the region:
| Location | Address | Pick-up Hours |
| Burford | County of Brant Administrative Office 26 Park Avenue | Monday to Friday 8:30 a.m. to 4:30 p.m. |
| Paris | County of Brant Customer Service Office 66 Grand River Street North | Monday to Friday 8:30 a.m. to 4:30 p.m. |
| St. George | St. George Public Library 78 Main Street North | Please check the website for hours. |
| Scotland | Scotland Public Library 281 Oakland Road, PO Box 40 | Please check the website for hours. |
Boil water advisories
When water becomes unsafe, the Health Unit may issue boil water advisories (BWAs). These require residents to boil water for drinking, cooking, and brushing teeth until the advisory is lifted.
If your business or property provides drinking water to the public but does not use a municipal supply, you may be operating a Small Drinking Water System (SDWS).
- SDWS are regulated under Ontario Regulation 319.
- Public Health Inspectors assess each system’s risk level (low, medium, or high).
- Owners and operators may receive directives for water testing, treatment, and training.
- Public Health monitors these systems and issues advisories (for example, boil water advisories) when needed to protect users.
GEPH regularly inspects public pools, public spas, splash pads, and wading pools, and offers online courses in pool operations.
Backyard pool safety
A safe pool is a fun pool. The tips below, developed with GEPH and the Canadian Red Cross Water Safety Services (Brantford), can help you keep your backyard pool healthy, safe, and enjoyable for everyone.
Circulation and filtration
Good water circulation keeps your pool clean and clear:
- Removes colour, particles, organic material, and some bacteria
- Improves the effectiveness of sanitizers like chlorine
- For best results, run the filter 24 hours a day, 7 days a week
Backwashing
- Begin backwash when the pressure difference between influent and effluent pump lines reaches 10–15 psi (or follow your installer’s recommendations).
- Backwashing reverses water flow through the filter to remove trapped dirt.
Water balance
Balanced pool water is safer for swimmers, easier to maintain, and more cost-effective.
Recommended ranges:
- Total Alkalinity: 80–120 ppm
- Free Chlorine: 0.5–1.5 ppm
- pH Level: 7.2–7.8
- Temperature: 70–90 °F
Contact us for advice on other water quality parameters.
Saltwater pool maintenance
- Adjust control knob to meet demand
- Maintain proper salt and stabilizer levels
- Inspect pool regularly for filtration and chlorination
- Keep recirculation system running at all times
- Test salt levels every six months
- Ensure chlorine is being produced (check for green light)
- Clean the cell to remove calcium deposits
Safe chemical storage
Do:
- Read and follow manufacturer’s instructions
- Wear protective equipment when handling chemicals
- Store in a cool, dry, ventilated, and locked area
- Keep chemicals off the floor and at a reasonable height
- Store dry chemicals above liquids
- Clean up spills immediately
Don’t:
- Store near flammable materials (paper, solvents, paint, etc.)
- Mix different chemicals
- Leave containers open
- Use the same scoop for multiple chemicals
Pool fencing
A proper fence helps prevent accidents and unauthorized access:
- Minimum 1.2 m (4 ft) in height
- Gaps narrower than 10 cm (4 in)
- Self-closing and self-latching gate with latch inside and out of children’s reach
- Prevents direct access from house or yard
- Free of climbable objects (trees, furniture, etc.)
- Always locked when the pool is not in use
Check local bylaws for additional requirements.
Safety equipment checklist
Keep these items near your pool:
- Lifesaving equipment (e.g., safety ring with rope)
- First aid kit
- Telephone with emergency numbers posted nearby
- Properly fitted personal flotation devices (PFDs) for toddlers and beginner swimmers
Pool rules
Do:
- Enter feet-first
- Use slides feet-first only, with one person at a time
- Ensure diving boards and slides match pool manufacturer’s guidelines
- Keep deck clear of debris
- Cover the pool securely when not in use
Don’t:
- Leave swimmers unattended
- Allow running on the pool deck
- Mix alcohol with swimming
- Dive in cloudy or murky water
- Dive into above-ground pools
- Use earplugs (they can cause pressure issues during descent)
- Use breakable glassware near the pool
Emergency steps
- Check: Look for danger; tap and ask “Are you okay?”
- Search: If responsive, check for bleeding from head to toe
- Care: Open airway, check breathing and pulse, treat injuries
- Call: If unresponsive, call for help and have someone dial 911
With the right preparation, your backyard pool can be a safe and enjoyable place for family and friends.
Sodium is a nutrient found in table salt and many other foods. Your body needs some sodium to function, but too much may lead to high blood pressure (a major risk factor for stroke, heart disease and kidney disease). Most Canadians take in more than twice the amount of sodium they need in a day.
For a healthy adult, the level of sodium in the water supply does not pose a risk to health. However, if you or members of your family have kidney disease, heart disease, high blood pressure or liver disease, and need to restrict your salt intake because of these illnesses, please ask your physician or health care professional how sodium in the water may affect your health.
The Guidelines for Canadian Drinking Water Quality and Ontario Drinking Water Quality Standards set an aesthetic objective for sodium in drinking water at 200 mg/L, at which point it can be detected by a salty taste by the average person. A maximum acceptable concentration for sodium in drinking water has not been specified.
The Safe Drinking Water Act, the Ontario Drinking Water Systems Regulation (Ontario Regulation 170/03), requires that a report be made to the local Medical Officer of Health if a sodium result is higher than 20 mg/L in a sample of drinking water so that local physicians and other health professionals can be advised of this to help those on sodium restricted diets control their sodium intake.
Healthy adults (14-50 years old) should consume between 1500 and 2300 mg of sodium each day; however, for individuals on sodium restricted diets, the amount of sodium in the water may be significant. When sodium levels in drinking water are at 20 mg/L, drinking 2 litres per day would contribute 40 mg of sodium to a person’s diet.
For healthy adults, this level of sodium in drinking water does not pose a health risk; however, for people on a very strict sodium restricted diet of 500 mg per day, this would contribute about 8% of their daily sodium allowance.
When sodium levels are higher than 20 mg/L, the Medical Officer of Health is required to inform the public, through health professionals, in order to help people on sodium-restricted diets control their sodium intake.
The bacteriological safety of municipal drinking water is not affected by sodium levels, meaning that the water is safe to drink.
In Ontario, sodium is required to be sampled in municipally treated drinking water every five years. In addition, all sodium levels in excess of 20 mg/L must be reported to the Medical Officer of Health.
Grand Erie Public Health periodically notifies local physicians of elevated sodium levels in our municipal drinking water in order for them to advise their patients with sodium-restricted diets accordingly.
Nitrates are naturally occurring substances that are essential for plant growth and are typically found at low levels in groundwater and surface water. However, human activities can increase nitrate levels in drinking water sources.
Common sources of nitrate contamination include:
- Fertilizers used in agriculture, lawns, and gardens
- Animal manure (e.g., feedlots, dairies, poultry farms)
- Septic systems and wastewater
- Landfills and refuse dumps
Nitrates are colourless, odourless, and tasteless, so testing is the only way to confirm their presence.
Nitrates dissolve easily in water and move quickly through soil into groundwater.
The risk of contamination increases with:
- Excess fertilizer not absorbed by plants
- Sandy or gravelly soils
- Porous or fractured bedrock
- Heavy rainfall or flooding
- Poorly constructed or maintained wells
Wells that are shallow, older, dug, or affected by flooding are more vulnerable to contamination
High levels of nitrates in drinking water can pose a health risk.
The most significant concern is methemoglobinemia (blue baby syndrome), a condition that reduces the blood’s ability to carry oxygen.
Vulnerable populations include:
- Bottle-fed Infants under 6 months of age
- Babies up to one year old
- Pregnant individuals
Infants are particularly at risk because their digestive systems can convert nitrate into nitrite, which interferes with oxygen transport in the blood. This can result in a bluish tint to the skin and, in rare cases, can be life-threatening.
Older children and adults are generally at lower risk. Some people have a genetic predisposition to developing methemoglobinemia and may be more susceptible than others. There is no conclusive evidence linking nitrates to cancer, although long-term exposure to high levels may pose some health concerns.
The Ontario Drinking Water Standards set a Maximum Acceptable Concentration (MAC) for nitrates at:
10 mg/L measured as nitrate-nitrogen.
This standard is designed to protect health over a lifetime of consumption.
If your water test exceeds this level:
- Retest to confirm the result
- Be aware that nitrate levels may fluctuate over time
- Do not use water with high nitrate levels (> 10 milligrams per Litre) for drinking or preparing infant formula
- Do not boil water to remove nitrates—boiling will only increase the concentration of nitrates
- Bathing and showering are safe, as nitrates are not significantly absorbed through the skin
If nitrates are present above safe levels, treatment options include:
- Reverse osmosis
- Ion exchange
- Distillation
These systems can be effective but may be costly. Alternatively, you may consider:
- Using bottled water
- Installing a cistern
- Drilling a new, deeper well (if a safe water source is available)
Prevention is the most effective way to protect your drinking water. Measures to protect your drinking water from nitrates include:
- Ensure proper well construction and maintenance
- Inspect wells regularly for cracks or improper seals
- Locate septic systems at least 50 feet from wells and downhill from them
- Avoid storing or mixing chemicals near the well
- Protect wells from flooding and surface runoff
- Have your well water tested regularly. A list of laboratories licensed to perform drinking water tests in Ontario is available at: https://www.ontario.ca/page/list-licensed-laboratories
- Older or shallow wells should be tested more frequently, as they are more at risk of contamination.
- Test your well also for bacteria. High nitrate levels could indicate potential contamination from human or animal waste.
For more details and guidance, please see:
Gas Wells
Companies and landowners in Ontario have drilled thousands of wells to extract oil and gas deep underground. Abandoned wells are those that are no longer needed for oil and gas extraction and have been sealed, though they can still leak if not properly decommissioned. Orphaned wells, on the other hand, lack a legal owner responsible for them and can be inactive, suspended, abandoned, or even active. The key difference is that orphaned wells have no one to ensure their safety and maintenance, increasing the risk of environmental and health issues.
If not properly decommissioned, abandoned oil and gas wells may leak hydrogen sulphide or methane gas.
Hydrogen Sulphide (H2S)
Exposure to low concentrations (10-100 ppm) of hydrogen sulfide may cause:
- Irritation to the eyes, nose, or throat
- Difficulty in breathing for some people with asthma
- Headaches
- Poor memory
- Tiredness
- Balance problems
Brief exposures to high concentrations of hydrogen sulfide (greater than 500 ppm) can cause a loss of consciousness. In most cases, the person will likely regain consciousness without any other effects. However, in some people, there may be permanent or long-term effects such as headaches, poor attention span, poor memory, and poor motor function. In very high concentrations, death is possible due to respiratory paralysis.
Learn more about hydrogen sulphide here.
Methane Gas (CH4)
Methane is present in the atmosphere, is non-toxic, and creates no hazard when inhaled in limited quantities. However, if large quantities of natural gas or methane replaces the air, lack of oxygen may result in:
- mood changes
- slurred speech
- vision problems
- memory loss
- nausea
- vomiting
- facial flushing
In severe cases, there may be changes in the breathing and heart rate, balance problems, numbness, and unconsciousness.
To determine if your property has a gas or oil well, start by searching online maps and resources.
- Use the Petroleum Well Map to find out if there is a record of a well on your property.
- Use the Oil, Gas and Salt Resources Library Petroleum Well Map if you have an oil or gas well on your property and want to view more detailed records.
Speak with long-standing neighbours or local well drillers who might have knowledge of well locations. Walk your property systematically to look for signs of abandoned wells.
The following sites or signs may indicate an abandoned well:
- Farm properties with multiple farmsteads, abandoned structures, uncultivated sites or sinking land.
- In farm areas with stunted vegetation, compacted trails, oil residue, or abandoned drilling pads.
- Patches of dead vegetation or soil staining.
- A rotten egg smell caused by hydrogen sulphide.
- Natural gas bubbling or oil odours in well water.
For additional information, visit: Locating existing water, gas or oil wells | ontario.ca
If you discover a well on your property that is not in the above databases, or you are not sure, contact the Petroleum Operations Section (Email: POSrecords@ontario.ca | Telephone: 519-873-4634)
There are thousands of known abandoned wells across Ontario including in the GEPH region. The Abandoned Works Program is a program offered by the Ministry of Natural Resources to help Ontarians properly plug wells on their property. Landowners with gas wells can contact the Ministry to determine if their well qualifies for the program.
If you find an abandoned gas well on your property:
- Report It: Contact the Ministry of Natural Resources (MNR) to report the well, especially if it does not have a record. This helps future generations of land users and developers. The Ministry can advise if your well qualifies for the Abandoned Works Program.
- Professional Assessment: Hire a licensed well technician to assess and manage the well.
- Plugging and Sealing: Inactive wells should be properly plugged and sealed by removing piping and using a mechanical or cement plug.
- Reclamation: Restore the land to its natural state after plugging the well.
- Monitor: Regularly check the site for any signs of leakage or environmental impact.
Following these steps helps protect public health and the environment.
If you notice a rotten egg scent and suspect a hydrogen sulphide or methane gas leak:
- Near your home, call the Spills Action Centre of the Ministry of Environment at 416.325.3000 or 1-800-268-6060 (toll-free)
- Inside your home, call your local fire department — In Norfolk County │ In Haldimand County | In Brantford | In County of Brant
Climate Change
Climate change refers to long-term changes in temperature, precipitation, wind patterns, and other climate indicators. These shifts are already affecting the health and well-being of people across our communities and around the world.
The health impacts of climate change include:
- Increased cases of heat-related illness and death due to more frequent, severe, and prolonged heat waves
- Higher risk of injury and illness from extreme weather events such as floods, storms, and wildfires
- Worsening of respiratory conditions and higher risk of cardiovascular disease
- Greater exposure to vector-borne diseases carried by ticks and mosquitoes
- Increased risk of food- and water-borne illnesses from contamination caused by heavy rainfall
- More sun-related conditions such as sunburn, skin cancer, cataracts, and other UV-related eye damage
- A rise in climate-related stress, anxiety, and other mental health concerns
- Potential impact on food supply and affordability due to extreme weather affecting local and imported crops
At GEPH, we assess how climate changes is affecting local health outcomes and identifying populations most at risk, as well as supporting communities across our region to prepare for, adapt to, and reduce these health impacts. We are committed to working with municipal partners, community groups, and health organizations to raise awareness and develop local strategies for both climate change mitigation and adaptation.