Presentation on Livermore Lab Site 300 Superfund Cleanup Peter Strauss, Environmental Scientist, PM Strauss & Assoc. Community-Wide Meeting on 9-28-17

Location Site 300 is nearly 11 square miles in the Altamont Hills and about 6 miles southwest of downtown Tracy. The Site has been surrounded by open space used mainly for ranching and recreation (Carnegie SVRA). Tracy Hills development of 5500 homes has been approved near the boundary. 7.1 million people live within 50 miles of Site 300.

What functions are performed at Site 300? Measures the physical and explosive properties of all the components of nuclear weapons, except the fissile materials (e.g. plutonium). Analysis of controlled explosions, vibration and shock testing, and fabrication and machining of shaped explosives.

Testing At Site 300

Major Contaminant Releases Volatile organic compounds (VOCs) High explosive compounds Radioactive hydrogen (tritium) Depleted uranium Nitrate Perchlorate Polychlorinated biphenyls (PCBs) Dioxins and Furans

Location of Major Contaminant Releases

Why Site 300 is of Concern Cleanup of the site is expected to take at least 50 years. There are still small areas in the southern boundary where off-site groundwater cannot be used for drinking water. Open-air “firing tables” were used to conduct tests. Many of these facilities were set in canyon areas – when detonations occurred, the airborne particles covered the hillsides. The highest baseline human health risk assessment estimated a cancer risk of 1 × 10–3 (one in one thousand) for onsite workers inhaling VOC vapors.

Why Site 300 is of Concern There are threatened and endangered species at Site 300, and contaminants pose what is called an ecological risk. Site 300 overlies a “regional groundwater” system, that is used for irrigation and drinking water wells. This groundwater is a potential drinking water source and is a protected resource. There are proposals by DOE and other parties to alter the national clean-up strategy for “Complex Sites” that may remove some protections for Site 300.

Why Site 300 is of Concern Understanding Risk What does 10 to the minus 3 mean? What is acceptable risk? EPA requires that the acceptable risk range is an increase in lifetime cancer incidence from 1 in 10,000 to 1 in one million. Most states and EPA try to achieve one in one million. Cancer incidence rate in the US is approximately 30% If the cancer rate is so high, why should we care? What do toxicity and risk mean? Toxicity is the hazard of a substance which can cause harm. Risk is a measure of the probability that harm will occur under defined conditions of exposure to a chemical. Is there uncertainty in risk calculations? Did you ever sign up for this incremental risk?

Progress to Date Before Site 300 was listed on the Superfund, one groundwater plume of solvents extended off-site for over a mile along the Corral Hollow stream bed. Tritium concentrations in groundwater have been reduced by one order of magnitude (from over 2 million picocuries per liter to over 200,000 picocuries per liter). It still exceeds drinking water standards (20,000 picocuries per liter). The plume that is above drinking water standards has also been significantly reduced. Capped and closed landfills, high explosives rinse water lagoons, “dry wells” and burn pits

Progress to Date Constructed a drainage diversion system to prevent groundwater from rising into the landfills and releasing contaminants to the groundwater Operate up to 20 groundwater and soil vapor extraction and treatment systems Consolidated and solidified 29,000 cubic yards of PCB-, dioxin-, and furan-contaminated soil at Building 850 Sampled more than 680 groundwater monitor wells to track plume migration and remediation progress

Outstanding Issues Remediating areas contaminated by depleted uranium (Building 812 firing table and Building 851 firing table). Remediating perchlorate in numerous areas. Continued monitoring of the various groundwater plumes, retarding further migration of on-site plumes, pulling the rest of the off-site plume back on site. Evaluating airborne risks – ongoing activity, including some open-air testing, regular controlled burning, and accidental burning. Ensuring that cleanup remains a priority and that Tracy area communities are consulted in decision-making.

Studies Underway Treatability Study at B-834 to reduce nitrate Treatability Study at B-854 to reduce perchlorate

Upcoming Decisions and Studies B-851 (scope) B-812 (Feasibility Study followed by public hearing) Monitored Natural Attenuation for perchlorate at B-850