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REGIONAL WATER BOARD REWNSE (SWRCB/OCC FILE A-1886) • -8- PETITION FOR REVIEW OF WAT'T'E DISCHARGE REQUIREMENTS ORDER NO. R5-2007-0113 (NPDES NO. CA0079243) CITY OF LODI, WHITE SLOUGH WATER POLLUTION CONTROL FACILITY CONTENTION G: EFFLUENT LIMITATIONS FOR OIL AND GREASE REQUIRED The Permit does not contain an effluent limitation for oil and grease in violation of federal regulations 40 CFR 122.44 and California Water Code, Section 13377 Based on information included in self-monitoring reports submitted by the Discharger, the effluent oil and grease was non-detectable (<5.0 mg/L) in 9 of 36 samples in 2006. The maximum effluent concentration was 0.8 mg/L on 17 February 2006. Therefore, the discharge does not have a reasonable potential to cause or contribute to an in-stream excursion above the Basin Plan's narrative objectives for oil and grease and floating material. The previous permit, Order 5-00-031, included monthly average and daily maximum effluent limitations for oil and grease of 10 mg/L and 15 mg/L, respectively. The new Order removes the effluent limitations for oil and grease based on new information consistent with anti-backsliding requirements of 40 CFR 122.44(I)(2)(i)(13)(1). CONTENTION H: ACUTE TOXICITY EFFLUENT LIMITATIONS INADEQUATE The Permit contains an effluent limitation for acute toxicity that allows mortality that exceeds the Basin Plan water quality objective and does not comply with federal regulations, at 40 CFR 122.44 (d)(1)(i) The Order contains several mechanisms to ensure that the effluent discharge does not cause acute or chronic toxicity in the receiving water. Receiving water limits proscribe the discharge from causing toxicity in the receiving water. For effluent limitations included for the protection of the aquatic life beneficial use, the Order includes end-of-pipe effluent limits that were developed based on aquatic life toxicity criteria. Furthermore, the Order requires whole effluent chronic toxicity testing, which identifies both acute and chronic effluent toxicity. If this testing shows that the discharge causes, has the reasonable potential to cause, or contributes to an in stream excursion of the water quality objective for toxicity, the Order requires the Discharger to investigate the causes of, and identify corrective actions to eliminate the toxicity. The acute whole effluent toxicity limits establish additional thresholds to control acute toxicity in the effluent: survival in one test no less than 70% and a median of no less than 90% survival in three consecutive tests. Some in-test mortality can occur by chance. To account for this, in the EPA acute toxicity test method, the test acceptability criteria allow ten percent mortality (requires 90% survival) in the control. Thus, the acute toxicity limits allow for some test variability, but impose ceilings for exceptional events (i.e., 30% mortality or more), and for repeat events (i.e., median of three events exceeding mortality of 10%). These effluent limitations are consistent with U.S. EPA guidance. In its document titled "Guidance for NPDES Permit Issuance", dated February 1994, it states the following beginning on page 14: "In the absence of specific numeric water quality objectives for acute and chronic toxicity, the narrative criterion 'no toxics in toxic amounts'applies. Achievement of the narrative criterion, as applied herein, means that ambient waters shall not demonstrate for acute toxicity: 1) less than 90% survival, 50% of the time, based on the monthly median, or 2) less than 70%