Cemex is forming plans to fire up its kiln after Thanksgiving while some residents say they’re worried about health impacts from chromium VI contamination, and are frustrated by what they say has been a slow process of testing air samples to determine if the carcinogen has lingered while the plant has sat mostly idle.
The Cemex kiln, originally turned off in early September due to a decrease in cement demand, has remained dormant since potentially-harmful levels of the cancer-causing chromium VI showed up in air monitoring tests released in October by the Monterey Bay Unified Air Pollution Control District.
The levels of chromium VI detected by the air district in tests conducted in June to August were nearly 10 times higher than the allowable limit set by the state.
The chromium was traced to cement dust from the 100-year-old factory blown down wind.
Levels of chromium VI measured in recent weeks by the air district and independent environmental consultants hired by the county Environmental Health Department have dropped significantly since the plant has limited operations to loading trucks with cement.
However, air district officials and county leaders say the real test comes once the plant resumes full operations.
Cemex officials laid out their plans to restart the kiln during Tuesday’s Board of Supervisors meeting, which included at least a dozen North Coast residents voicing concerns about health issues and whether results of continued air testing are being done in a timely manner.
"To not address the full range of health effects adds insult to injury," Davenport resident Nancy Calhoun said. "In my small sample, I’ve already talked to people who’ve experienced nose bleeds, diarrhea and sinus attacks. One cannot say for sure if all these adverse health effects are because of exposure to toxic dust."
County health officials have said testing residents is not a step they would take at this point in the ongoing chromium VI investigation.
Cemex Vice President Satish Sheth said the company would like to prepare the kiln for production after Thanksgiving.
Sheth said the kiln would run for only a week and then shut down again to await test results that pinpoint any chromium VI still in the process.
Temporary kiln operations would be an "unprecedented" move in the cement industry, Sheth said, because of the tremendous amount of energy required to heat it to the 2500°F, and higher, required to make cement.
"Firing up the kiln is not an immediate process. It requires a lot of maintenance, and it takes at least two days to bring it to the full temperature," Sheth told supervisors. "We are taking extra precautions, and are confident the data will prove we are doing the right thing."
The company plans to suspend the use of high chromium materials such as mill scale and steel slag and replace them with the more expensive iron ore when restarting the kiln. Those materials, common for cement manufacturing, can turn into chromium VI when heated at high temperatures.
The kiln will only resume if tests from clinker grinding done on two days last week come back with minute levels of chromium VI. Those test results are expected by the end of this week, Sheth said.