Further intensive point source investigations were performed in certain areas in cooperation with DOFM personnel. These sites were targeted because of past complaints or reports, results of bacteriological testing, information from faculty and other personnel, as well as visual appraisals. A DOFM sanitary sewer system map updating program done simultaneously with this study was also useful in discovering some problems.
Through dye testing it was discovered that sewage from Hilgard Hall was emptying into the North Fork. Through a combination of extensive deterioration and dislocated joints, the sanitary line coming from Hilgard Hall was leaking sewage into an adjacent storm sewer line. This storm line emptied directly into the North.Fork at the West Circle tunnel. Based on the badly deteriorated condition of the sanitary line, this situation could have existed for as many as ten years. This sanitary line will either be replaced or inversion lined as soon as possible.
Dye testing also uncovered a potential contamination problem at Le Conte Hall. It was found that all the laboratory sink drains in the old section of Le Conte were routed directly into the South Fork of the creek near the Faculty Glade (Point #15). This was a result of both changing building codes since the building was built in 1924 and deteriorated piping. Chemical sampling of this continuous effluent showed no chronic chemical contamination problem at the time of sampling. This effluent will be rerouted to the sanitary sewer system as soon as possible.
Acting on information supplied to EH&S, a massive sewage contamination problem was uncovered at Memorial Stadium. Extensive deterioration of the sanitary sewer lines coming from the stadium was causing considerable infiltration of sewage into the Little Inch bypass culvert which also runs underneath the stadium. The bypass culvert emptied the sewage into the South Fork of the creek at the Faculty Club. This situation was occurring every time the Stadium was in use.
To determine the extent of sewage contamination, bacteriological sampling was conducted during three football games in the Fall. Results of this sampling is given in Table 23. This shows massive surface water contamination, especially on 9/5/87. A section of sanitary sewer was inversion lined before the
9/26/87 football game. It appears that the sewage contamination was somewhat mitigated by this action, but not solved. Further evaluation of this problem was hindered by lack of manhole access in this area. A manhole has since been constructed and investigation of the problem is continuing.
Results of chemical analyses (Section 4.3) and visual signs of possible sewage contamination prompted investigation into a 3011 RCP storm line emptying into the South Fork by Harmon Gym (Point #68). The storm line was electronically traced and sewage was noted in a catch basin along the line in the Zellerbach parking garage. Further dye testing revealed that bathrooms in the Bear's Lair Pub which were installed about two years ago had been mistakenly routed to the storm sewer rather than the sanitary sewer system. The bathrooms have been shut down pending repair of this plumbing problem.
The heating plant discharge (Point #106) into the Main Branch of the creek also poses a problem. This constant discharge of hot water has sporadically been a source of thermal pollution, depending on the temperature and volume of effluent. Elevating the temperature of a water body reduces the solubility of oxygen and can also have an adverse effect on aquatic organisms. The discharge has averaged about 44.8° C (Table 21), but has been observed to be as high as 60° C (140° F). On July 22, 1987 the ambient temperature of the Main Branch was raised from 18° C to 32° C, a rise of 14° C (25° F). This is in violation of the RWQCB standard which prohibits the elevation of ambient water temperature by more than 5° F. The hot water originates from a still used to make distilled water for laboratory use in the Life Sciences Building. A drainage line then returns this water to the heating plant, but the heated water is not pure enough to be recycled through the new high pressure cogeneration boiler system so it is discharged into a storm drain at the plant. This thermal discharge should be rerouted to the sanitary sewer system.