FIELD DOCUMENTS - Laserfiche WebLink

Home Browse Search

WASTE DISCHARGE REQL&MENTS ORDER NO. R5-2004-002* -5- CITY OF MANTECA, CITYLATHROP AND DUTRA FARMS WASTEWATER QUALITY CONTROL FACILITY SAN JOAQUIN COUNTY 9. Clean Water Act Section 303(a-c), required states to adopt water quality standards, including criteria where they are necessary to protect beneficial uses. The Regional Board adopted water quality criteria as water quality objectives in the Basin Plan. The Basin Plan states that"[t]he numerical and narrative water quality objectives define the least stringent standards that the Regional Board will apply to regional waters in order to protect the beneficial uses." The Basin Plan includes numeric and narrative water quality objectives for various beneficial uses and water bodies. This Order contains Receiving Water Limitations based on the Basin Plan numerical and narrative water quality objectives for biostimulatory substances, chemical constituents, color, dissolved oxygen, floating material, oil and grease, pH,pesticides, radioactivity, salinity, sediment, settleable material, suspended material, tastes and odors, temperature, toxicity, turbidity, and electrical conductivity. Numeric Basin Plan objectives that are applicable to this discharge and which have been incorporated as Receiving Water Limitations include: a. Dissolved Oxygen—The Basin Plan includes a water quality objective that within the legal boundaries of the Delta, the dissolved oxygen concentration shall not be reduced below 5.0 mg/1 in all Delta waters except in those waters designated otherwise. Numeric Receiving Water Limitations for dissolved oxygen are included in this Order and are based on the Basin Plan objectives. b. pH—The Basin Plan includes numeric water quality objectives that the pH"...not be depressed below 6.5 nor raised above 8.5. Changes in normal ambient pH levels shall not exceed 0.5 in fresh waters with designated COLD or WARM beneficial uses." Numeric Receiving Water Limitations for pH are included in this Order and are based on the Basin Plan objectives for pH. C. Turbidity—The Basin Plan includes a water quality objective that"[i]ncreases in turbidity attributable to controllable water quality factors shall not exceed the following limits: • Where natural turbidity is between 0 and 5 Nephelometric Turbidity Units (NTUs), increases shall not exceed 1 NTU. • Where natural turbidity is between 5 and 50 NTUs, increases shall not exceed 20 percent. • Where natural turbidity is between 50 and 100 NTUs, increases shall not exceed 10 NTUs. • Where natural turbidity is greater than 100 NTUs, increases shall not exceed 10 percent. " A numeric Receiving Water Limitation for turbidity is included in this Order and is based on the Basin Plan objective for turbidity.