The latest testing at a popular Westport swimming beach appear to show an all clear for E-coli.
Earlier samples over summer had flagged contamination from cattle, according to a report to the West Coast Regional Council.
The test site in question, Marrs Beach on the south side of the Buller River has been a focus for the regional council for years however it has had difficulty tracing the sources of e-coli contamination.
Martins Creek enters the river near Marrs Beach and council has formed a catchment group to try and address contamination issues with landholders in the catchment.
Water quality sampling results provided alongside a report to the council's Resource Management Committee gives an overview of results for November 2023 to March 2024.
In the main, the majority of 20 sites tested through summer were in the 'very low risk' category for swimmers.
However beaches around Westport periodically blipped through summer.
Marrs Beach had two flags, in mid-November and mid-January, where testing found the water was of 'moderate to high risk' to swimmers due to E.coli exceedances (between 550 and 280 per 100ml).
Shingle Beach on the opposite side of the Buller River had three moderate to high risk flags: one in mid-December and two through the middle of January.
Other exceedance of water quality standards across the region included one moderate to high risk flag each in mid-January at the popular Taylorville swimming hole in the Grey River, and at Nelson Creek; at Westport North Beach (mid-December) and Punakaiki River (mid-January).
The council undertakes weekly contact recreation water quality sampling at the swimming spots from the end of October to late March.
The report to this week's Resource Management Committee said the last sampling period from February 19 to March 20 did not flag any exceedance despite "significant rainfall" preceding sampling in some locations.
Escherichia coli (E. coli) is a bacteria commonly found in the lower intestine of warm-blooded organisms. Some E.coli strain can cause serious food poisoning.