COMPLIANCE INFO_JTD 9/3/2025 - Laserfiche WebLink

Home Browse Search

WASTE DISCHARGE REQUIREMENTS ORDER R5-2015-0058-01 -18- SAN JOAQUIN COUNTY DEPARTMENT OF PUBLIC WORKS FOOTHILL SANITARY LANDFILL, INC. FOOTHILL LANDFILL SAN JOAQUIN COUNTY Following an indication of a release, verification testing must be conducted to determine whether there has been a release from the landfill unit or the detection was a false detection. The detection of two non-naturally occurring waste constituents above the MDL as a trigger is appropriate due to the higher risk of false-positive analytical results and the corresponding increase in sampling and analytical expenses from the use of one non- naturally occurring waste constituent above its MDL as a trigger. 75. For a naturally occurring constituent of concern, Title 27 requires concentration limits for each constituent of concern be determined as follows: a. By calculation in accordance with a statistical method pursuant to Title 27, section 20415(e)(8); or b. By an alternate statistical method meeting the requirements of Title 27, section 20415(e)(8)(E). 76. Title 27 specifies the prescriptive requirements and performance standards applicable to monitoring data analysis and requires that such methods be implemented as follows: a. As specified in the existing MRP under the WDRs; or b. In accordance with a technical report (certified by an appropriately registered professional) documenting such methods, submitted to, and approved by, the Central Valley Water Board; or c. In accordance with any water quality data analysis software deemed appropriate for such use by either the Central Valley Water Board or SWRCB. The MRP of these WDRs requires that concentration limits for naturally-occurring constituents be based on an interwell approach absent a satisfactory demonstration that an intrawell approach is justified at the site (e.g., existence of significant spatial variability not attributable to a release from the unit). Consistent with monitoring reports submitted under previous WDRs, MRP No. R5-2015-0058 specifies that the method of Interwell Tolerance Limits be used to calculate concentration limits for naturally-occurring constituents at the site. For evaluation of corrective action progress (i.e., trends), the monitoring program specifies an intrawell statistical procedure (e.g., Sens Slope Method). See Section C.4, MRP. 77. To demonstrate that corrective action has been completed (i.e., concentrations along Point of Compliance returned to compliance with the water quality protection standard), Monitoring Specification G.7 specifies a four year “proof” period. During this period, the Discharger must demonstrate that all constituents of the release have been reduced to concentration limits for at least eight consecutive semiannual monitoring events.