Since 2003, radioactive materials are known to be leaking from Hanford into the environment: "The highest tritium concentration detected in riverbank springs during 2002 was 58,000 pCi/L (2,100 Bq/L) at the Hanford Townsite. The highest iodine-129 concentration of 0.19 pCi/L (0.007 Bq/L) was also found in a Hanford Townsite spring. The WHO guidelines for radionuclides in drinking-water limits levels of iodine-129 at 1 Bq/L, and tritium at 10,000 Bq/L. Concentrations of radionuclides including tritium, technetium-99, and iodine-129 in riverbank springs near the Hanford Townsite have generally been increasing since 1994. This is an area where a major groundwater plume from the 200 East Area intercepts the river ... Detected radionuclides include strontium-90, technetium-99, iodine-129, uranium-234, −235, and −238, and tritium. Other detected contaminants include arsenic, chromium, chloride, fluoride, nitrate, and sulfate."