CHARLESTON, W.Va. — A bill changing how the state measures discharges into the state’s waterways has cleared both chambers of the Legislature and is headed to the Governor’s desk. The state Senate passed HB 2506 Tuesday without making any changes.

The bill adopts the “harmonic mean” criteria for calculating the rate of stream flow in determining permit limits for pollution discharges. Harmonic mean represents average stream flow rather than the current measurement based on the lowest seven-day waterway flow over a ten-year period.

The bill also allows for overlapping “mixing zones,” the points where discharges mix with water and become diluted. Those permits would only be allowed with the approval of the state Department of Environmental Protection with EPA review.

The West Virginia Manufacturer’s Association pushed the bill arguing that the current permitting requirements are too stringent and that the changes have no impact on water quality standards. Senate Judiciary Committee Chairman Charlie Trump (R-Morgan) made that point during floor debate Tuesday.

“So what I want to say to my colleagues and to the citizens of West Virginia who I’m sure are deeply interested in this issue, this will cause no harm or degradation┬áto the waters of this state,” Trump said.

However opponents argued the changes mean more pollution will be discharged into the state’s waterways. “This bill as it currently stands will make us less stringent than our surrounding states,” said Senator Corey Palumbo (D-Kanawha). “So we will allow more pollutants to go into our water.”

The Senate approved the bill 20-13-1.