Testing times for our water

In Kāpiti safe drinking water is available at the turn of a tap – and something we all take for granted.

Our great track record on managing our ‘three waters’ (drinking water, wastewater and stormwater) is due to a focus on strategic planning and investment by Council over many years. As a district, this has allowed us to reduce water use, quickly detect and repair leaks, pay one of the lowest water rates in the country and only for what you use, and ensure a reliable water supply even over dry summers and winter droughts.

Our water quality testing laboratory, tucked away in a small nondescript building beside the Paraparaumu Wastewater Treatment Plant, plays a crucial role in keeping our water safe.

The laboratory gained full IANZ accreditation for testing drinking water within a record time of 10 months, after the government mandated this strict standard for all drinking water testing laboratories following the campylobacter outbreak in Havelock North in 2016. This event sickened about 5,500 people, hospitalised 45, and has been linked to three deaths and ongoing health complications for an unknown number of people.

The lab’s responsibilities are many and varied. Our three full-time and two part-time highly qualified and experienced staff monitor and test our drinking water supply seven days a week.

They check we’re meeting our resource consent conditions for disposing of stormwater and treated wastewater back into the environment. They also monitor leachates from the Otaihanga landfill and operate a commercial service checking the safety of private water supplies from bores and roofs around our district. Greater Wellington, the regional council, contracts our lab to monitor our district’s rivers and beaches for bacteria and toxic algae to check they’re safe to swim.

The lab takes in about 5,500 samples each year, but our small team of scientists and technicians generates about 25,000 individual results, with some tests taking five days to complete. Each drinking water sample, for example, undergoes at least two tests – one for temperature on arrival to the lab and one for bacteria (total coliforms and E.coli).

It’s an extremely rare occurrence, but if a sample were to fail the maximum acceptable bacterial levels it would be reported straight away to the Aotearoa New Zealand drinking water regulator Taumata Arowai, the water treatment plant manager, and IANZ.

It would immediately trigger an investigation by the water treatment plant staff, including retests and wider checks. If necessary, Council would have to issue a ‘boil water notice’ until the issue is identified and resolved.

We’re one of the few councils in Aotearoa to still operate our own lab. Manager Kim Mazur says this provides many benefits and efficiencies for the community.

“A big advantage is that Council water and wastewater specialists can respond immediately if we query a result because we work right next door.

“Having an in-house laboratory also means samples are processed faster. If there is a problem with the drinking water or wastewater plants, or a sewer pipe bursts, for example, the lab team is contacted and resamples can be processed immediately. Results can be turned around much faster.

“It’s the same with toxic algae – we can get an immediate alert out to the public. All the staff here are locals. We know the area so well that if there’s a change in bacteria levels we ask why and can get the team out immediately to check if there’s been a sewer breach.”

Staff local knowledge, for instance, identified that toxic algae remained at dangerous levels throughout winter 2023. This is highly unusual as normal winter rainfall would provide flushing flows to remove any residual toxic algae from the summer season.

“We weren’t physically monitoring for toxic algae because in the past this was normally only done in summer. It’s only because one of our staff was walking her dog along the Waikanae River that we identified that it was present. We went down to do a check, and it was bad,” Kim says.

“We now do monthly toxic algae monitoring in the rivers over winter unless there’s been a flushing flow, which means we don’t need to.”