Niagara Monitoring Hub Frequently Asked Questions

Swim Drink Fish’s Niagara monitoring hub has been testing water on Lake Erie this summer. With the recent media attention on recreational water quality at Sugarloaf Harbour in Port Colborne, many people have been reaching out to us for information that will help them understand the sampling process and results.

Here’s a list of some frequently asked questions with answers to help you understand lake water quality so you can enjoy and protect Lake Erie.


Frequently Asked Questions

Q: Why do you test water every week?

Swim Drink Fish community monitoring hub staff test water in the same locations at least once a week so that the results are as up-to-date as possible. Many local governments in Ontario, including Niagara Region, also monitor weekly.

Q: Can I rely on test results from last month or last year? Why do you need to keep sampling over and over again?

Water quality is like weather — it changes all the time. Water that meets government guidelines one day may fail the next day. This does not mean that the old results were wrong. It just means that conditions changed.

Q: Samples from early in the week passed, but it rained hard last night. Is everything still okay?

Water quality is constantly changing, so you should use your best judgement when you are going into the water. Rain, changing wind conditions, or other factors may mean that test results from even one day ago may no longer be accurate. Swim Guide includes the historical pass/fail information for each beach location to help you understand how often conditions change.

Q: What are you testing for?

We test for E. coli bacteria. This is the official indicator of recreational water quality in lakes and rivers in Ontario and most of the world.

We also do extensive field surveys and Environmental Health and Safety Surveys so that we understand the sites we monitor. The more time we spend at a site, the more our understanding improves. We do not use the information in these surveys to inform our pass/fail results, though.

Q: Why would water samples meet guidelines last week but fail this week? How can the results be different for the same location?

Water quality results may be very different from one day or week to the next. Bacteria generally doesn’t survive more than a few days in the lake. If there are infrequent sewage spills or rains, then bacteria will be high for a few days and low the rest of the time.

If bacteria levels are always high, it means that sewage or stormwater is flowing into the water often (and sometimes constantly).

Q: Why might water samples collected on the same day fail in one place and pass in another place?

Water quality is very localized. Test results from samples collected a few metres away from each other can be very different. Pollution tends to be highest near its source, more persistent in warmer water, and slower to flush away where water is contained by break walls and other barriers. In Toronto Harbour, for example, bacteria levels tend to drop as you move away from the sewage outfalls in the harbour walls towards the open water in the middle of the harbour.

Water quality results from one place, like Sugarloaf Harbour, don’t apply to other places on Lake Erie. Every location is different, so we never make broad generalizations about water quality in an entire community or lake.

Q: When does a water sample “fail” to meet government guidelines?

There are two ways that samples can "fail” to meet government guidelines.

  1. If any single sample of 100 ml of water has 400 E. coli or more, it fails to meet government guidelines;

  2. If the geometric mean of at least 5 samples collected from a recreational water area in a 30-day period has 200 E. coli or more per 100 ml of water, the site fails to meet government guidelines.

This guideline comes from the Operational Approaches for Recreational Water Guideline, 2018, issued by the Ministry of Health and Long Term Care in Ontario. It is based on the federal Canadian Recreational Water Quality Guidelines.

Q: What is a “geometric mean”?

“Mean” is the math word for “average". When you say that the average temperature for this time of year is 25 degrees celsius or talk about a baseball player’s batting average, you are also talking about “means”.

A geometric mean is a more complex way of calculating an average that is representative of many samples. You can use when you are dealing with numbers that vary widely so that outliers do not distort your final result. Outliers are unusually high or low numbers.

If you want to understand the gist of the government guidelines for water quality, think of the geometric mean result as an average and you have the general idea.

Q: How many samples do you take to generate a water quality result?

Swim Drink Fish collects at least 5 samples at every site, every time we monitor. We collect samples from the same location every time, following the protocols in government guidelines.

Q: What is the highest level of E. coli you have found at Sugarloaf Harbour to date?

As of August 1, 2019, the highest single sample E. coli result we found at Sugarloaf Harbour was more than 2419.6 E. coli units. This is the maximum bacteria count that the monitoring system can provide. Results were at or above 2419.6 E. coli on June 18, June 25, July 9, July 16, and July 23. Four of the 6 samples came from the lake directly south of HH Knoll Lakeview Park.

The highest geometric mean we found at Sugarloaf Harbour was 1611.74 on June 25, 2019.

Q: What is the lowest level of E. coli you have found at Sugarloaf Harbour to date?

As of August 1, 2019, the lowest single sample E. coli result we found at Sugarloaf Harbour was more than 4.1 E. coli units on July 4, 2019. This sample was collected from the floating dock off of Marina Drive.

The lowest geometric mean we found at Sugarloaf Harbour was 24.48 on July 4, 2019.

Q: When is water “safe” for swimming?

Government guidelines for water quality are all based on risk assessments. Health Canada estimates that there will 10-20 illnesses for every 1,000 people who swim in waters that meet government guidelines. That rate of 1-2% is considered an acceptable level of risk by government officials. Once bacteria levels exceed government guidelines, the risk of contracting an illness increases.

Q: Why do you monitor water quality at places that are not traditional “beaches” or where people aren’t “swimming”?

Swimming is the first thing most people think of when they think of recreational water, but there are lots of ways people use water and depend on good water quality. Kayaking and small-craft sailing, for example, often take place in harbour areas where people don’t swim. People engaged in those sports often submerge their heads in the water and need it to be “swimmable”. Similarly, people who surf, wakeboard, paddle board and fish are in the water year-round or far from traditional beaches. They, too, need water to be “swimmable."

Q: What is a community water quality monitoring hub?

Swim Drink Fish currently operates hubs in Toronto, Niagara - Lake Erie, Zhiibaahaasing First Nation, and Vancouver.

Hubs focus on popular places for swimming or watersports activities that are not currently monitored by other organizations or agencies. Staff are trained to conduct water quality monitoring programs that follow government guidelines and international best practices and communicate the results to the public through our Swim Guide app. Hubs also prepare annual reports on their findings to identify opportunities to restore, protect, and promote local waters.

Community monitoring hubs are a direct response to growing demand for reliable, affordable recreational water quality information. The purpose of the hubs is to help more people connect with the water in more places more often. This promotes physical and mental health, increased environmental awareness, and helps to stimulate sustainable local economic development.

Q: Who does the monitoring and sample analysis?

Each monitoring hub is managed by a trained, professional coordinator. The coordinator oversees sample collection and analyzes the test results in our lab. Each step of the sample collection, processing, and analysis follows established government protocols and international best-practices for water quality monitoring.

Q: How are water test results shared?

Pass/ fail results are shared via our Swim Guide app. The free app is available for download from iTunes and Google Play. The web version is online at

The detailed sample results are published via our open data portal.

At the end of a monitoring season, Swim Drink Fish also prepares a report summarizing the monitoring results, identifying water quality trends, and suggesting next steps for protecting the local environment and public health. These recommendations may take one to three years to develop, depending on monitoring location conditions.

Q: Can I get test results from Swim Drink Fish staff if I see them in the field?

Samples must be incubated for about 24 hours before they can be analyzed. When we are in the field collecting samples, we do not yet know what the water quality results will be for that day. If you want to know the recent test results, please check

Q: How does E. coli get into the water?

E. coli are found in the intestinal tract and faeces of humans and warm-blooded animals. The bacteria gets into the water in two ways. It can be dumped into the water from a sewage pipe, stormwater outfall, boat, person, or similar direct source. It can also run into the water from the land when there is rain, groundwater flow, or flooding. E. coli is the indicator for recreational water quality because there is a strong correlation between high E. coli levels and gastrointestinal illness.

E. coli is generally linked to human sewage, especially in urban areas. It can also come from droppings from birds like geese.

Q: What are the public health risks associated with high E. coli levels?

Some types of E. coli can cause illness, vomiting, diarrhea, and in rare instances serious disease or infection. We use E. coli levels as an indicator of contamination, but it is not the only contaminant of concern when bacteria levels are high. High E. coli levels are also associated with other contaminants in the water that may have harmful health impacts, including cholera, typhoid, dysentery, schistosomiasis, hepatitis A, and salmonella.

Q: Will people be scared away when they learn there is bacteria in the water?

No, not if you give them enough information to understand the situation. Sometimes at first the shock of learning your favourite swimming hole has a pollution problem can be alarming. But we all understand that weather changes daily, so it’s not hard to understand that water quality is the same way. In every community where access to frequent, reliable water quality information has improved, people have rallied to restore and protect swimmable water.

Q: When is a “no swimming" advisory issued?

In Ontario, medical officers of health issue swimming and other public health advisories. Monitoring organizations typically report pass/ fail results but do not issue advisories.

Q: I saw you demonstrating water testing on TV. Was that part of your monitoring program?

No. From time to time Swim Drink Fish will provide a demonstration to media to explain how the sampling process works. Media reports from CHCH TV in the Niagara Region do not depict Swim Drink Fish staff conducting water quality tests.

Q: Where and when did you first share water testing results from Niagara?

Water quality results from Niagara region were first shared with the public via Swim Guide and the open data portal, as described above. A detailed description of the monitoring program was also presented to stakeholders in the region early in the season so that the location, frequency, and monitoring protocols were known. Swim Drink Fish does not embargo water quality information or limit the release of our data for exclusive media interviews.

Q: Why is data transparency important?

People should have access to water quality data so that they can make informed decisions about where and when they want to connect with water. Some people will willingly accept an elevated level of risk in order to spend more time on the water or compete in an event. Others will limit exposure to contaminants because of health concerns or a compromised immune system. In order to protect people’s ability to make informed choices, Swim Drink Fish developed an open data exchange standard to make data-sharing among experts and monitoring agencies easy. Swim Drink Fish also supports open government initiatives that release full water quality monitoring results to the public.

Q: Are there other water quality guidelines for E. coli?

Yes. The Provincial Water Quality Objective for E. coli in Ontario is less than 100 E. coli units per 100 millilitres of water. The number is based on the geometric mean of 5 samples, similar to the federal guideline. There is no single-sample maximum. This objective takes into consideration protection of both human health and aquatic life. Prior to 2018, this was the threshold for issuing swimming advisories at Ontario beaches. Some municipalities, including Toronto, continue to use this threshold.

There are also guidelines for boaters and people who are near the water but are not fully submerging their heads. Those “secondary” water users are less likely to contract a waterborne illness, so the Canadian Recreational Water Quality Guideline is met if the geometric mean of at least 5 samples collected from a recreational water area in a 30-day period has less than 1,000 E. coli per 100 ml of water.

Q: Should contaminated areas be closed to the public?

Swim Drink Fish gets its name from our communities’ need for swimmable, drinkable, fishable water. Our position is that all people should have access to clean water and that putting up permanent “no swimming” signs is not an appropriate response to water quality problems. In our experience, when people are banned from accessing the water, pollution and public health problems get worse and local businesses suffer. The best solution to water quality concerns is restoration and protection.

Q: Would you swim in the Great Lakes?

Yes! The Great Lakes offer some of the best open water swimming experiences in the world. Pollution concentrates in specific locations and water quality changes daily, so you should always check Swim Guide or your local government monitoring service to find places that meet health guidelines.