SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

WASTE DISCHARGE REQUIRE TS GENERAL ORDER NO. R5-2008-0 4 IN-SITU GROUNDWATER REMEQIATION AT SITES IMPACTED BY VOLATOORGANIC COMPOUNDS, NITROGEN COMPOUNDS, PERCHLORATE, PESTICIDES, SEMI-VOLATILE COMPOUNDS, HEXAVALENT CHROMIUM AND/OR PETROLEUM HYDROCARBONS duration; (4) best practicable treatment and control, including adequate monitoring and hydraulic control to assure protection of water quality, are required; and (5) the discharge will not cause WQOs to be exceeded beyond the treatment zone and it is expected that increases in concentrations above WQOs caused by the treatment will be reduced over time. A slight residual increase in salts may occur at some sites subject to this Order but will be limited to a maximum 10 percent increase over background and less than the WQO listed below in Finding No. 15. See Groundwater Limitation E.3. 15. This Order addresses water quality as it relates to the chemicals being injected, as well as the byproducts and breakdown products produced by the reactions of the injectants, chemicals being treated and geological materials. Cleanup criteria for groundwater are established in an appropriate enforcement document — Record of Decision, Cleanup and Abatement Order, or Remedial Action Plan and are not discussed further as a part of this Order. As discussed above, chemicals are injected to stimulate reduction in concentrations of the target waste constituent and the target waste constituent may undergo a series of transformations to other constituents as it degrades. The injected chemical itself may leave residuals of its components, as well as cause changes in groundwater chemistry that liberate metals found in the formation materials. Background/baseline concentrations of metals and total dissolved solids will be established pursuant to the attached Monitoring and Reporting Program. The applicable WQOs are the narrative toxicity objective, Primary and Secondary Maximum Contaminant Levels, and the narrative taste and odor objective as found in the Basin Plan. Numerical limits in this Order implement those WQOs. The following Table presents the numerical WQOs for potential waste constituents of concern at the site: Constituent WQO Reference trichloroethene 0.8 /L California Public Health Goal tetrachlorethene 0.06 /L California Public Health Goal vinyl chloride 0.05 /L California Public Health Goal cis 1,2-dichlorethene 6 /L Primary Maximum Contaminant Level 1,2-dichlorethene 10 /L Primary Maximum Contaminant Level 1,2-dichloroethane 0.4 /L California Public Health Goal 1,1-dichloroethene 6 /L Primary Maximum Contaminant Level 1,1-dichloroethane 3 /L California Public.Health Goal 1,2,3-trichloro ro ane 0.0007 /L Draft California Public Health Goal 1,2-dichloro ro ane 0.5 /L California Public Health Goal 1-chloro ro ane 280 /L IRIS propene 28 /L Taste and Odor iron 300 /L Secondary Maximum Contaminant Level manganese 50 /L Secondary Maximum Contaminant Level hexavalent chromium 2 /L Draft PHG total chromium 50 /L Primary Maximum Contaminant Level total dissolved solids 450 m /L Food and Agricultural Organization sulfate 250,000 /L Secondary Maximum Contaminant Level sodium 20,000 /L USEPA Health Advisory bromate 10P9/L Priarnry Maximum Contaminant Level chloride 1 106,000 /L Agricultural Water uality Goal— Food and A