Laserfiche WebLink
t <br /> i -6- <br /> FACT SHEET ORDER NO. 5-00-03 1 <br /> ATTACHMENT C <br /> CITY OF LODI <br /> WHITE SLOUGH WATER POLLUTION CONTROL PLANT <br /> SAN JOAQUIN COUNTY <br /> g) Chlorine <br /> Chlorine in the receiving water is extremely toxic and has reasonable potential to be discharged at <br /> significant concentrations. The Discharger monitors both chlorine residual and sulfur dioxide <br /> .residual. By maintaining a low residual (positive amount) of sulfur dioxide in the effluent, the <br /> Discharger is relatively certain that there is no residual chlorine present in the effluent. <br /> Additionally, the Discharger monitors chlorine residual as a means of permit compliance. The <br /> current effluent limitation for total residual chlorine is 0.1 mg/l as a daily maximum. The USEPA <br /> developed ambient water quality criteria for chlorine to protect freshwater aquatic organisms. <br /> EPA's ambient water quality criteria for protection of aquatic life are 11 µg/l as a 4-day average <br /> (chronic) concentration, and 19 µg/l as a 1-hour average (acute) concentration for total residual <br /> chlorine. EPA guidelines and the Basin Plan allow for mixing zones where water quality objectives <br /> can be exceeded, but no lethality is allowed. Therefore, this Order contains effluent discharge <br /> limitations for total residual chlorine of 0.01 mg/l as a weekly average, and 0.019 mg/l as an hourly <br /> average based on the ambient criteria to protect aquatic life. <br /> h) Electrical Conductivity (EC) <br /> Electrical conductivity is listed under the California 303(d) list as a water parameter causing <br /> impairment to portions of the Sacramento-San Joaquin Delta and San Joaquin River. This listing is <br /> based partly on increased salinity of surface waters experienced by stakeholders during previous <br /> drqught conditions. The impaired area is for the southern one-third of the Delta, upstream of the <br /> current discharge location. The Basin Plan objective for EC in the San Joaquin River at Jersey <br /> Point (downstream of the discharge location) strives for an EC of between 740 to 2,200 µmhos/cm <br /> depending on flow conditions of the river. This objective has been established to protect beneficial <br /> agricultural uses of the river. Review of Discharger self monitoring data from January 1998 <br /> through September 1999 indicates that the EC of the effluent ranged from 550 to 700 µmhos/cm <br /> and that the average EC measurement during periods of surface water discharge was 622 <br /> µmhos/cm. Based on this information no specific effluent limitation for EC will be required by this <br /> permit. However, this Order requires EC to be monitored in both the receiving waters and the <br /> effluent. This monitoring will allow for a better understanding of salinity trends of the receiving <br /> waters and what the impact of the discharge has on those waters. <br /> i) Trace constituents <br /> Federal regulations require effluent limitations for all pollutants that are or may be discharged at a <br /> level that will cause or have the reasonable potential to cause, or contribute to an in-stream <br /> excursion above a narrative or numerical water quality standard. Based on information submitted as <br /> part of the application, in studies, and as directed by monitoring and reporting programs some <br /> constituents were regularly detected which were evaluated for the potential to exceed water quality <br /> criteria. Also, chlorine is used at the wastewater treatment plant as a disinfectant and, based on <br /> experience, has a reasonable potential to be discharged in toxic concentrations. Staff has used both <br /> Basin Plan numeric water quality objectives and EPA's ambient water quality criteria as a means of <br /> deriving a numeric limitation to protect the receiving stream from toxicity as required in the Basin <br />