Air Quality - Part II

1. Health Risk Calculations Systematically Understate Risk. The DEIR’s health risk assessment systematically and substantially understates the Quarry’s health risks to individuals (in addition to the averaging error discussed above). For example, one variable in the calculation estimating toxic air contaminants requires inputting the number of wheels on the trucks transporting materials from the Quarry (the more wheels, the greater the emissions). The calculation assumed that Quarry trucks have 6 wheels. Virtually all of them in fact have 18. Dr. Damian describes many other examples of risk understatement, and could find no significant example of risk overstatement.
2. 2001 Study Ignored. The DEIR summarizes the results of site-specific air quality monitoring tests performed by Sonoma Technologies, Inc. (STI) in 2004 and 2005, which failed to pick up much PM-10 material at all, and went on to conclude that, generally, Quarry air is cleaner than non-Quarry air. These testing results are inconsistent with the DEIR’s air quality modeling predictions and with residents’ widely documented experience with the fine, gray dust that settles on their properties The DEIR ignores the results of a County-commissioned study performed by Onsite Environmental Laboratories, Inc., which was finalized in a report dated March 15, 2001, and which was pointed out in our Initial Study comment letter. That report found loads of excessive PM-10 and PM-2.5 material. It would have been prudent and sensible, at a minimum, for the DEIR to have made some attempt to reconcile these studies.
3. Enclosure Alternative. The DEIR considers no fundamental changes to the Quarry's operations that would substantially reduce the emission rates of C-silica. The most obvious change would be the enclosure of the most offensive aspects of the operation, such as the barge loading operation and the rock crushers. We encourage you to read an article from Pit & Quarry, April 1, 2008. The Quarry has historically resisted making substantial capital investments that would make their operation more tolerable to nearby residents, asserting that such measures would be too costly. They instead take credit for modest operational changes, such as increased watering of trucks, encouragement of truck tarping and an improved sweeper. Though these measures may be modestly helpful, they do not come close to making the Quarry a “best practices” operation. The EIR should conduct a best practices study on how quarries have dealt with residential encroachment, beginning with the South Dakota quarry featured in the Pit & Quarry article described above.
4. No Continuous Monitoring of Air Quality. The DEIR provides for no continuous independent monitoring of toxic air contaminants, an obvious mitigation step.