This is the last of a four-part series of articles supplied by Beyond Plastic Bermuda in support of its Take Back the Tap campaign

Bermuda’s water-catch system is the envy of many around the world, and as countries strive to become more sustainable in the face of climate change, some look to our white-stepped roofs and tank storage as pioneering designs.

In recent years, however, many island residents have become concerned about the quality of the water stored in their tanks and have resorted to buying bottled water as an alternative. This is an unnecessary expense to your purse, to your health and to our environment.

Water in plastic bottles is not as healthy as the marketing would have you believe. Not only does bottled water potentially contain hundreds of thousands of micro and nanoplastics, but the chemicals in the plastic containers themselves can leach into the water. Some of these chemicals have been linked to diabetes, obesity and infertility, and, most recently, microplastics have been linked to the spread of colorectal cancer.

As part of our Take Back the Tap campaign, Beyond Plastic Bermuda has conducted research into what exactly could be in our tanks that residents are concerned about, and how to effectively filter it out so you can have confidence in drinking your “Bermuda roof water”.

What might be in our tank water?

The most common contaminant in our tank water is microbial; however, chemical compounds have also been tested for in recent years, especially in the area around Belco. The easiest way to find out how clean your tank is, is to get it tested. The Ministry of Health offers two types of water-testing service — bacterial and chemical. Each test costs $34. Bacterial testing looks for total coliforms and E. coli. Chemical testing looks for chloride, hardness, nitrate and pH.

There has been nothing commonly found in our tank water, however, which cannot be removed without the correct tank and roof maintenance, filtration, or by installing a small reverse osmosis system. This includes in homes close to Belco and the Tynes Bay waste-to-energy facility.

Since Belco’s North Power station was commissioned in March 2020, there have been regular studies on the tank water of properties in the vicinity. These studies were funded by Belco but managed by the Bermuda Institute of Ocean Sciences and assisted by the Pollution Control Section of the Department of Environment and Natural Resources. Further analysis was conducted in 2021, 2022 and 2023.

The latest water-sampling report found that combustion-related compounds measured in tank water were typically present in quantities below the most stringent drinking-water standards. These standards are the UK Water Supply Regulations 2016, US National Primary and Secondary Drinking Water Regulations, and the World Health Organisation drinking-water guidelines 2017.

In light of what they know about the quality of Bermuda’s tank water and the worst-case scenarios, we asked DENR scientists who were involved in the water sampling, if they would drink their tank water — and they both said they did, but they do use filters. Geoff Smith uses a point of use micro and nanofiltration system with activated carbon, “just as a precaution”, and hydrogeologist Shaun Lavis uses a Brita water filter, saying “it’s definitely cheaper for me to do it that way than it is to buy bottled water”.

How to prevent microbial contamination

Microbial contamination means your tank water contains coliforms. These are bacteria commonly found in the environment such as in soil or vegetation, as well as animal intestines. Having coliform bacteria in your water tank does not necessarily cause illness, but their presence indicates that your water supply may be vulnerable to contamination by more harmful microorganisms, such as E. coli.

By cleaning and maintaining your tank, roof and the pipes in between, you can help prevent microbial contaminants as well as the build-up of sediment. By law, tanks should be cleaned every six years, but the Ministry of Health actually advises cleaning “as often as necessary to prevent sediment accumulation”.

How to safely filter your water

Periodically chlorinating your tank is one way to kill bacteria. And, as long as your roof and tank are cleaned and well maintained, water filter jugs such as Brita, or sink and refrigerator water filters, should make your tap water safe to drink. Drinking water can also be boiled to kill bacteria.

Another option is to install a reverse osmosis system. This uses pressure to force water across a semi-permeable membrane to remove salt and other impurities such as bacteria, allowing only fresh water through. Small reverse osmosis systems can be installed to filter water at its point of use.

There are also a variety of other filtration systems which can be either installed at point of entry or at point of use. These include UV purification systems, which neutralise bacteria, parasites and micro-organisms; nanofiltration, which is effective in removing bacteria as well as viruses; and carbon filters, which can remove aluminium, chlorine, chloramines, sediment and certain trace metals. They can also remove pesticides and herbicides.

If you are concerned about the quality of your tank water, the ideal treatment system is one that incorporates sediment, carbon, UV filtration and nanofiltration. As long as these are correctly maintained and the filters are changed when needed, these systems will ensure that your drinking water is free of all common contaminants.

While there are costs associated with filtration systems, they are still cheaper than the cost of relying on bottled water, but, more importantly, they are cheaper than the costs to your health of drinking water that contains microplastic and has been stored in plastic.

• Erich Hetzel is a local environmentalist and member of Bermuda Environmental Sustainability Taskforce. Katie Berry is a local environmentalist and a Beyond Plastic champion. For full details about Beyond Plastic Bermuda’s findings regarding tank water and water filtration options, read Take Back the Tap at https://beyondplastic.bm/drinking-water-in-bermuda/

Part 1

Part 2

Part 3