They want salt levels in the Lower Hunter monitored as part of the Hunter River Salinity Trading Scheme, which currently measures salinity as far down-river as Singleton.

NSW Environment Protection Authority (EPA) is conducting a 10-year statutory review of the scheme, which allows coal and power industries to pump salt water into the river in return for credits they buy and redeem.

Lower Hunter Agricultural Water Users Association member Stephen Osborne said salinity levels were “extremely high” in the Lower Hunter in recent months.

Mr Osborne, whose produce includes potatoes, pumpkins and watermelons, said the review should consider measuring salinity levels in the Lower Hunter, beyond Singleton.

“The water leaves a white film and burns the edges of the leaves,” he said  “When we have the hot, westerly wind, everything seems to go backwards.”

An information session will be held at Hunter Convention Centre, in Singleton from 12.30pm today.

Phoenix Park vegetable farmer John Wright said he did not use Hunter River water on his produce if he could help it.

Mr Wright, a fifth generation farmer, said his produce did not grow as well when he used river water for irrigation and salinity was a concern.

“The water gets down here and just goes back and forward with the tide, not much of it seems to run out into the ocean,” he said.

A recent EPA discussion paper said most scientific evidence suggested current scheme salinity targets should not be raised.

EPA North Branch director Gary Davey said the review would ensure regulations governing the scheme continued to meet their objectives.

“Before the scheme was introduced in 2002, there was significant tension between primary producers and industry, as discharges from industry significantly increased salinity levels in the water making it unsuitable for irrigation,” he said.