State environmental regulators want tighter water pollution standards at the Northeast’s only commercial hazardous waste landfill because of an ongoing risk that toxic contaminants could potentially move into area waterways.

The state Department of Environmental Conservation has proposed five new testing points on the site of CWM Chemical Services, the facility in northwestern Niagara County that discharges stormwater into tributaries of Fourmile and Twelvemile creeks and treated wastewater into the Niagara River.

New sampling points would, among other things, help pinpoint the source of contamination of PCBs, or polychlorinated biphenyls, a toxic substance previously found on the site that is tied to cancer and long banned in the United States, according to the agency.

“. . . [N]ew internal monitoring points for PCBs are being proposed,” the agency said in a September report, “due to known upgradient contaminated soils, past violations and the concern for their migration to stormwater.”

The tightened standards also are aimed at preventing dilution, which would effectively “mask the presence” of contaminants, the agency said.

As part of the overall proposal, regulators want to lower the limits for the discharge of mercury from the site by 40 times, though CWM will have an interim period with a higher limit the first 18 months after the permit is changed.

Changes to the facility’s State Pollutant Discharge Elimination System, or SPDES, permit are going through their second draft by the agency. The first draft was issued in October 2007.

Any company in the state that discharges into waterways is supposed to have a SPDES permit; this includes municipalities that have their own wastewater treatment plants.

This type of permit is generally

modified once every 10 years, DEC Water Division engineer Gerard A. Palumbo told the CWM Citizens Advisory Committee earlier this month.

Permits are automatically renewed by the state after five years, because federal law limits the length of this permit to five years, Palumbo said.

CWM opposes some of what the agency wants, arguing, in part, it should determine where exactly stormwater samples should be taken.

“Our goal is consistent with that of the DEC — to have safe discharge standards,” said company spokeswoman Lori Caso.

In reviews done in 2000 and 2005, state regulators found that environmental conditions in Fourmile Creek had become “severely impacted,” but the source or sources of the contamination could not be specifically identified.

In addition to the three new testing points for stormwater, regulators have proposed two new on-site sampling points for the treated wastewater that is eventually released into the Niagara.

Stormwater consists of rain or snow that falls on site but doesn’t come into contact with waste.

The wastewater includes precipitation that hits open landfills. The water is then collected, treated and stored until it is sent via underground pipeline to the river. Site wastewater also comes from liquid waste the company receives from customers and then treats.

The first new sample point would be between the preliminary and the advanced wastewater treatment phase. The second point, under the state’s proposal, would be placed after the wastewater is treated but before it’s moved to a holding pond.

The wastewater, which can be released at up to a million gallons per day, also is tested, and results are approved by the state before it’s sent to the river.

As has long been the case, stormwater is tested as it leaves the site—it is not held until the results of the sampling are known. At the advisory committee meeting earlier this month, Palumbo, the agency water engineer, said, “That’s our normal way of doing business.”

The treated wastewater is tested for about 77 chemical parameters, while the stormwater sampling is “more limited,” Palumbo said, noting tests for suspended solids and PCBs.

Testing for radiological contamination in water discharges from CWM does not fall under the SPDES permit. Last year, CWM asked the federal government to clean up radiological contamination on part of its property where it wants to build a new landfill.

Lewiston resident Amy Witryol said the agency’s water division has taken some “very appropriate steps” with this proposal in terms of minimizing the effect of dilution on sampling results.

“It’s because of that dilution we just don’t know how badly they’ve contaminated Four[mile] and Twelvemile Creek,” she said.

Witryol said she also is concerned because the state’s proposed changes eliminate the rights of the towns of Lewiston and Porter to have CWM pay for additional independent sampling.

The company already has the samples tested at an independent lab, said Caso, so the state shouldn’t require that the company fund additional testing.

Barry Boyer, an emeritus member of the Buffalo Niagara Riverkeeper’s board of directors, said his organization is in the process of developing official comments on the permit proposal to give to the agency.

Some of the issues being discussed internally at the Riverkeeper organization, Boyer said, include whether changes should be made to CWM’s discharge into the Niagara River in order to better accommodate habitat restoration, and if there’s a better way to treat stormwater that’s released from the site.

Public comments on the proposed permit changes will be accepted by the state through April 30, a deadline extended from March 22.