GreenTown Los Altos

Lehigh Quarry’s Toxic Impact on Local Air and Watershed.


Dec 2012


Lehigh Permanente Quarry
Photo: Anne Ernst

Lehigh Quarry and Cement Plant located at the base of Black Mountain in Santa Clara County, is in litigation with Sierra Club, Bay Area for Clean Environment (BACE), Midpeninsula Regional Open Space District (MROSD) and Bay Area Air Quality Management District (BAAQMD) stemming from its air and water emissions.  The main source of contention is the unusually high levels of mercury and selenium within this deposit of limestone. Compounding their emissions are weak regulations grandfathered for this seventy year old plant.  A GreenTown Los Altos meeting on December 6 hosted two speakers on Lehigh emissions, Gary Latshaw, Air Quality Chairman for the Loma Prieta Chapter of the Sierra Club and Alice Kaufman, Legislative Advocate for Committee for Green Foothills.

Mercury, a powerful neurotoxin linked to autism, Alzheimer’s disease, and other brain disorders, becomes airborne in the kiln during clinker  process of cement production.  Airborne levels of mercury measured six times higher during Lehigh production as compared to non-operational periods.  Latshaw presented rates of autism in neighboring school districts –  Cupertino Unified showed statistically higher levels of autism as compared to other Bay Area districts.  Nitrogen oxides, sulfuric oxides and particulate matter are other airborne emissions that exceed regulatory levels and correlate to health deprivations.  Alarmed by health risks for its residents, the towns of Los Altos and Los Altos Hills have jointly hired a consultant to propose abatement improvements to Lehigh’s emission stack.
Selenium, a reproductive toxin for aquatic life and their avian predators, leaches out of limestone when exposed to air or water.  Lehigh’s selenium rich limestone has been mined below groundwater resulting in formations of selenium rich ponds which are discharged to Permanente Creek at rates of 250,000 to 2,500,000 gallons/day. The Water Quality Objective for selenium is 5 µg/l but levels as high as 100 µg/l have been measured on site.  Selenium levels ranging from 13 to 81 µg/l in Permanente Creek are noted in Sierra Club’s lawsuit.  In humans, high levels (>350ug/day) of selenium can lead to kidney, liver, nervous and circulatory disfunction. Permanente Creek, listed as an impaired creek by Regional Water Quality C Board (RWQCB), also shows unhealthy levels of mercury, nickel, sulfates and molybdenum.
Sierra Club lawsuit trial is scheduled for summer of 2013, if a settlement has not been reached.
Take Action:
The following slideshows and documentation contributed by Alice Kaufman and Gary Latshaw.

Leave a comment