In any case, the state Department of Health has taken the approach that the public will be protected from exposure to harmful levels of all chemicals of concern in the geothermal fluid by the same methods used to keep down levels of hydrogen sulfide. Rules, at Last Would that it were so easy. Last March, the state Supreme Court sided with the plaintiffs in the case, Pele Defense Fund, and required the DOH to promulgate such rules, pursuant to statutory requirements. Proponents of geothermal development maintain that the rules are, if anything, overly strict. This, they claim, shows just how conservative the DOH standards are.
Critics discount such comparisons.
In fact, one of the independent consultants retained by the state to analyze the effects of the June 1991 blow-out at PGV stated that if one wants to use OSHA standards as a guideline in the establishment of ambient air quality regulations, a rule of thumb in the industry is to divide the OSHA standards by 420, which, in the case of hydrogen sulfide, yields a result of 24 parts per billion. That's just a tad under the 25 ppb standard that the state eventually adopted for hourly average emissions. But that standard has left many nearby residents unhappy. Finally, there are individuals who are sensitive to the effects of hydrogen sulfide at levels lower than those set by state rule. Indeed, chronic or repeated exposure to the gas may itself bring on heightened sensitivity.