The annual summer water quality tests have begun at Northland's popular beaches, rivers and lakes.
The Northland Regional Council (NRC) tests for bacteria to gauge the risk of people contracting gastrointestinal and other infections while swimming or during other forms of recreation.
During the testing period, hundreds of samples will be taken from 46 popular coastal sites and 13 freshwater locations, with results posted on the national environmental reporting website LAWA - www.lawa.org.nz.
Last summer 99.1 per cent (606 out of 611) samples at coastal sites and 89.4 per cent (161 out of 180) of samples at freshwater sites over summer met national ''guideline values'', meaning they were considered safe for swimming.
The results are forwarded to the Whangarei, Far North and Kaipara District Councils, the Northland District Health Board (DHB) and other interested parties.