SITE INFORMATION AND CORRESPONDENCE_1985-2004

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Pat Leary • - 2 - • 16 March 2000 the amount of sewage because there was no good estimate of the volume of sewage contained in the storm drain line prior to the rainstorm. The ditch discharges to Little John Creek which discharges to a slough near French Camp. At approximately 3:30 pm on 11 January 2000, the City took samples of the ditch contents. BOD, COD, coliform, ammonia,pH and temperature were measured at 5 locations. The data was submitted to the RWQCB on 3 February 2000. The BOD concentrations ranged from 56 to 93 mg/l; COD from 323 to 498 mg/l; all coliform samples were greater than 1600 MPN/100 ml; ammonia levels were 2.93 to 4.86 mg/l;pH ranged from 6.67 to 7.21; and temperatures ranged from 13.2 to 13.8 Celsius. The City traced the sewage back to a plugged sewer line. The plugged line had backed up sewage to a manhole at Yosemite Ave. near Pacific Street. The City found that the grouting on the invert of a sewer manhole on Yosemite Ave. near Pacific Street had deteriorated, allowing the backed up sewage to discharge into the soil surrounding the manhole. The sewage migrated within the soil over to the storm water pipe. There was a capped tee-off to the storm water pipe. The cap had somehow become damaged, allowing the sewage to enter the storm water pipe. Sewage traveled underground in the storm water pipe for several hundred yards before being detected in the open storm drainage ditch. The City's crew cleared out the plug in the sewer line and repaired the damaged manhole. The City appeared to have made good cleanup efforts to contain the effects of the sewage spill. The City should take measures to prevent a similar spill from occurring. All sewer manholes should be checked for grout deterioration, and repairs completed, if needed. Regular sewer maintenance should be performed to remove plugs before they cause sewage backups. In the future, if sewage spills do occur, the City should be reminded that the Office of Emergency Services must be contacted immediately. And, as part of the Standard Provisions of their APDES permit, they are also required to notify the RWQCB by telephone within 24 hours of the spill, and should confirm this notification in writing within 5 days. The written notification shall state the nature, time, duration, and cause of the spill, describe the measures being taken to remedy the spill, and what measures are taken to prevent recurrence, including,where applicable, a schedule of implementation. The City must also take all reasonable steps to minimize any adverse effects to receiving waters resulting from any discharge in violation of their NPDES permit. This includes any additional monitoring as necessary to determine the nature and impact of the non-complying discharge.