Local frac sand opponents want the city of Winona to reconsider requiring "fence line" air quality monitoring of frac sand dust at sand facilities in the city. After nearly a year of debate, the city approved the installation of state-run air monitors on the roof of the Winona YMCA, which recently began measuring diesel fumes and silica sand dust small enough to enter the lungs.
At the Citizens' Frac Sand Summit, a conference held by the Land Stewardship Project last month, plans were announced to push the city of Winona to require monitors at facilities.
In an interview, Minnesota Pollution Control Agency (MPCA) officials said that the YMCA monitors, which they are operating, should provide a good idea of the ambient amount of silica dust that is in the air throughout the city. However, dust levels may be higher near facilities that conduct activities like blasting or processing sand, they acknowledged. Members of Citizens Concerned about Sand Mining (CASM) have argued that Winona needs monitors at those sites, too.
"The YCMA monitors are great, because, as the MPCA says, they'll give a good idea of the ambient air in the city, but that doesn't protect people who live next door" to frac sand facilities, said area resident, CASM member, and monitoring proponent Joe Morse in an interview. "There are people living within a few hundred feet of these facilities," he continued. "There's no way that we know how much dust is coming off a facility and into the community unless it's monitored. That's the major public health concern here," he added.
Winona should wait and see what the results from the YMCA monitors are before installing more monitors, said University of Wisconsin — Eau Claire Associate Professor of Environmental Health Crispin Pierce in an interview. Pierce specializes in air quality and has been active in research on silica dust.
"I still do believe that the [dust] levels around frac sand plants are higher and I really appreciate [that Minnesotans] are taking these issues seriously," Pierce said. However, referring to data from the YMCA monitors, he added, "I would frankly want folks to take a good look at that and see if the whole town is getting a higher level than an equivalent-sized town that's not near a frac sand plant before saying, 'Hey we need more monitors that are just going to be a kilometer away.'"
While the YMCA monitors have begun collecting samples, data on how much respirable silica dust is in the air will likely not be available until this summer. The MPCA is still in the processing of hiring a lab to sort out sand dust from other particles captured in that monitor; the data available now shows the levels of all particles of a certain size and does not distinguish the levels of silica dust.
Pierce said that if the level of silica dust captured by that monitor is close to the health standard adopted by the Minnesota Department of Health as dangerous, then "that would send up a red flag." If it is well below the benchmark, "that gives public health officials a sigh of relief," he said.
The MPCA monitoring effort will continue for at least a year. "It seems that the city needs to consider what it's going to do to protect people in the meantime," Morse argued.
CASM will meet with the city of Winona's Citizens Environmental Quality Committee (CEQC) on Tuesday at 4 p.m. in the Heritage Room at city hall to discuss facility monitors. The CEQC proposed facility monitors last summer as part of series of recommendations that led up to the YMCA monitors. The MPCA has offered to conduct the monitoring, if the city were to require it; however, either the sand facilities or the city would have to pay for it. The Planning Commission and the City Council opted not to support facility monitors. Planning Commission Chair Craig Porter argued that the city has already decided how to handle the issue of frac sand dust: the current zoning requirement that sand stockpiles be kept damp. MPCA officials have said that wetting sand is an effective way to mitigate dust emissions.
Frac sand dust a hazard?
City leaders and regulators alike have noted that preliminary data from the Minnesota Pollution Control Agency (MPCA) monitors at the Shakopee Sands mine near Jordan have not exceeded the health benchmark for respirable silica dust adopted by the Minnesota Department of Health and other states. Data from two other Minnesota sites and the sand dust measurements from the YMCA monitors are not available yet. The Wisconsin Department of Natural Resources (WDNR) recently posted results from air monitoring efforts throughout the state that indicate that frac sand sites are far below federal limits for larger coarse dust particles, that is, particles of ten microns in size or less (PM10). The Wisconsin data does not, however, give a clear indication of how much silica dust of four microns in size or less (PM4) is being emitted. The Minnesota Department of Health's benchmark is based on that size of silica dust, that, state officials say, is most closely linked to health risks.
The Wisconsin data is available at http://dnr.wi.gov/topic/Mines/SilicaMap.html.