Laserfiche WebLink
Thornton Sewer Plant 2 29 April 2014 <br /> San Joaquin County <br /> r <br /> be minimized through control of water depth, harvesting, or herbicides. C. Dead algae, <br /> vegetation, and debris shall not accumulate on the water surface." <br /> • Approximately 4.0 to 5.0 feet of freeboard was present in the pond system. <br /> • Odors associated with wastewater were not observed beyond the perimeter fencing. <br /> Since staff's last inspection in March 2013, attempts to repair erosion of the perimeter berm <br /> have failed. The liner on the berm is torn; exposing the berms to erosion from wind and wave <br /> action. In addition to creating irregularities in the berm surface, which are conducive to <br /> mosquito breeding, the erosion reduces the integrity of the pond berms. Without inner berms to <br /> segregate wastewater in individual ponds, performing routine inspections and maintenance to <br /> pond bottom is difficult and threatens to reduce pond percolation and increase the potential for <br /> berm seepage or overflow. <br /> Monitoring Report Review <br /> Staff has reviewed monitoring reports for the period of January 2013 through December 2013 <br /> and note that wastewater flows and pond freeboard are not being reported daily as required. <br /> Additionally, data for the annual sampling of the municipal water supply has not been submitted. <br /> Failure to report daily wastewater flows, wastewater pond freeboard, and the annual sampling <br /> results for the municipal water supply is a violation of the WDRs. Provision E.1 of Order 94- <br /> 101 states, "The Discharger shall comply with the Monitoring and Reporting Program No. 94- <br /> 101, which is part of this Order, and any revisions thereto as ordered by the Executive Officer." <br /> By 15 June 2014, the Housing Authority of San Joaquin County shall submit a Corrective Action <br /> Evaluation and Repair Plan, prepared by a registered California Professional Engineer to <br /> assess and repair erosion of the perimeter berm and restore inner pond berms as necessary to <br /> allow wastewater to be transferred, between ponds for maintenance and repair. Additionally, <br /> the plan shall contain a vegetation control program and a water balance demonstrating <br /> adequate storage and disposal capacity for both the average rainfall year and the 100-year <br /> return period annual total precipitation based on the following: <br /> a. Proposed storage pond geometry and capacity. <br /> b. Current and future wastewater and storm water flows distributed monthly in accordance <br /> with expected/historical monthly flow rates. <br /> C. A minimum of two feet of freeboard in each pond at all times. <br /> d. Historical local evapotranspiration, pan evaporation, and lake evaporation data (monthly <br /> average values). <br /> e. Local precipitation data with the 100-year return period annual total distributed monthly in <br /> accordance with mean monthly precipitation patterns. <br /> f. Projected long-term percolation rates. <br /> With regard to the monthly monitoring reports, effective immediately wastewater flows and pond <br /> freeboard shall be measured daily as required by Order 94-101. Furthermore, the results for the <br /> annual sampling of the municipal water supply shall be submitted with the June monitoring <br /> report, which is due on 20 July 2014. <br />