Results from weekly testing of water quality of popular Northland swimming spots will be posted online each Friday, starting November 30.
The Northland Regional Council's annual summer testing programme - this year involving taking hundreds of samples from 48 coastal and 11 freshwater sites - begins on November 26 andruns until the end of March 2013.
The results will be on www.nrc.govt.nz/swimming with more information available on freephone 0800 002 004. Anyone wanting to report concerns about water quality can ring the NRC's freephone 24/7 Environmental Hotline, 0800 504 639.
The samples will be given colour-coded grading: green for safe to swim, amber, elevated bacteria levels, and red, unsafe for swimming.
Environmental monitoring programme manager John Ballinger says the results will also be forwarded weekly to all three district councils, the Northland District Health Board and other interested parties. The NRC would inform the health board and the district councils of any results showing elevated bacterial levels within 24 hours.
"It's then the responsibility of the DHB and the district councils to take action," he said.
Action could include further site investigations to establish the source of any contamination, public warnings not to swim or gather shellfish; and putting up permanent warning signs at the worst sites.
Mr Ballinger said there were four simple strategies for anyone trying to judge water quality:
