Lake Ainsworth has again rated poorly in the latest NSW State of the Beaches report.
Lake Ainsworth has again rated poorly in the latest NSW State of the Beaches report. Marc Stapelberg

Faecal pollution or pristine waters: How swimming spots rate

IF YOU swim in Lake Ainsworth, you're risking exposure to faecal pollution.

But most North Coast ocean beaches are in pristine condition by comparison, according to the latest report on the condition of NSW swimming spots.

Ballina Shire Council and Richmond Valley Council were among the councils included in the study and the 2018-19 report, prepared by the Department of Planning, Industry and Environment, has found conditions in both LGAs were stable.

Most of the two shires' coastal beaches nabbed the highest rating of "very good" and were deemed suitable for swimming almost all of the time.

The exception was Ballina's Shelly Beach, which received the second highest rating.

The Evans River and the northern, eastern and western areas of Lake Ainsworth all claimed the second lowest score of "poor".

The report said those locations were "susceptible to faecal pollution and microbial water quality is not always suitable for swimming".

The Lennox Head lake's southern point, however, received a slightly better score and was found to have "generally good microbial water quality".

In the same category - and safe for swimming most of the time, except in the days after heavy rain - were all parts of Shaws Bay and The Serpentine in Ballina, as well as the waterway at Elm St bridge in Evans Head.

According to the report, particularly dry conditions experienced by the North Coast between November 2018 and April this year would have influenced conditions.

Ballina Shire mayor David Wright said the absence of a flood in that time would have helped to keep the region's beaches in top form.

Meanwhile, Lake Ainsworth's troubling conditions are the subject of an ongoing study through the Lake Ainsworth Coastal Management Program, being undertaken for the council by Hydrosphere Consulting.

However, the lake wasn't alone in receiving a "poor" score; only 26 per cent of lakes and lagoons in participating LGAs were rated as "good" or "very good", compared to 98 per cent of ocean beaches and 64 per cent of estuarine swimming spots.

Cr Wright said while the council would await Hydrosphere's full recommendations before taking any action, he believed increasing aeration in the lake would be on the to-do list.

"I'm not sure how much the solution is going to cost," Cr Wright said.

"When we've got all that information then we can apply for grants to get solutions."

Cr Wright said he was pleased with the shining report card for the shire's beaches, but he felt one thing was already a strong indicator of the quality along the coastal strip.

"I've just been down to Lennox for an hour (on Monday) and the people were everywhere," he said.

"If the water wasn't good or there was a problem, not as many would be there, but they are there."

Lake Ainsworth's blue green algae status is currently at green alert level, meaning there are no restrictions in place.