San Luis Obispo, CA Wallace Group provided engineering services to evaluate alternatives to correct existing sewer collection system deficiencies due to aging infrastructure and inflow/infiltration. The work was in response to regulatory requirements and Enforcement Order imposed by the Regional Water Quality Control Board.
On December 18, 2010, a severe winter storm downed a large tree in Chorro Creek, obliterating the existing 10” gravity sewer and bridge crossing that served 90% of the Cuesta College campus wastewater flows. Wallace Group, in conjunction with Fluid Resource Management, executed an emergency design-build of a 250-gpm temporary sewage lift station, in time for the January 18, 2011 start of school following winter break. The new temporary lift station and force main were completed within three weeks.
Following completion of the engineering evaluation and recommendations for long-term repair to sewer collection facilities, Wallace Group designed the improvements and successfully avoided the need for a permanent sewage lift station. The recommended project maintains gravity sewage flow, and provides for a new utility bridge crossing that also allowed for removal of an aging utility bridge with high potential for sewage leaks into Chorro Creek. The new gravity sewer and bridge project was completed in November 2011.