Pam Iorio, Mayor 306 E. Jackson St * Tampa, FL Wastewater Department. Overflow Report

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1 Page 1 / 7 Reported By: Owner: Name: FRED OCASIO with KCI TECHNOLOGIES Name:, Wastewater Department Location of Overflow: BRUCE B DOWNS BLVD Address: 306 E. Jackson Street Phone Number: Phone Number: (813) /15/2011 Time: 11:45 AM Received By: Name: OSCAR ESTRADA 3/15/2011 Time: 11:45 AM Date and Time of Discharge: Start 3/15/2011 Start Time: 11:45 AM Stop 3/17/2011 Stop Time: 4:45 PM Status of Discharge: Ceased Duration: 53 Hrs and 0 Mins Characteristics of Discharge: Raw Domestic and Industrial Estimated Volume: 5,800,000 Gallons Discharge (Rate of Flow): Variable GPM Recovered Volume: 1,800,000 Gallons Discharge Volume: 4,000,000 Gallons Source of Discharge: Cause of Discharge: Force Main Construction Activity - Contractor Was Discharge Contained on Site?: No Description of Area Affected: Cleanup Action Taken to Vacuumed by Sewer Cleaner Disinfected Area Trout Creek Description of Incident: See Next Page Where Did the Overflow Go?: See Next Page Steps Taken or Planned to Reduce, Eliminate, and Prevent Recurrence: See Next Page Other Agencies Contacted: Person Notified at State Warning Point: Officer 414 3/15/2011 Time: 2:46:00 PM Person Notified at EPC: Byron Bartlett 3/15/2011 Time: 2:39:00 PM Person Notified at DEP: Joe Squitieri 3/16/2011 Time: 8:49:00 AM

2 Description of Incident: Page 2 / 7 Wastewater Department personnel received a call at 11:45 AM on Tuesday, March 15, 2011 from Fred Ocasio with KCI Technologies, Inc., the firm providing construction engineering inspection (CEI) services for the Bruce B. Downs Boulevard widening project between Palm Springs Boulevard to Pebble Creek Drive, reporting a broken force main on the east side of Bruce B. Downs Boulevard near the end of the northbound off ramp from I-75. Crews were dispatched to the area, confirmed the overflow, and excavated the area to expose the existing 18-inch force main. Once the force main was uncovered, a 30-inch HDPE pipeline was discovered parallel to and in contact with the existing 18-inch force main where water was seen discharging from the 18-inch pipeline. Valves were exercised upstream of the break to isolate this section of the 18-inch force main and divert all wastewater flow into the parallel 24-inch force, ceasing the overflow at 12:15 AM on Wednesday, March 16, At 6:56 AM on Wednesday, March 16, 2011 Wastewater Department personnel received a call from Jim Barnes with Kamminga and Roodvoets, Inc., the prime contractor for the Bruce B. Downs widening project, reporting a broken force main at Bruce B. Downs Boulevard near Richmond Place. Crews were dispatched to the area, confirmed the overflow, and began excavating the area to expose the existing 18-inch force main. Simultaneously a contractor hired by the Wastewater Department was mobilized to set-up a temporary bypass around the apparent broken section of pipe (since the parallel 24-inch force main does not extend that far north and diverting the flow was not an option at that location). Once the force main was uncovered an old line stop connection (tapping sleeve and blind flange) was discovered with water discharging from between the tapping sleeve and force main where a torn portion of the gasket could be seen protruding. Wastewater engineering staff checked pressures in the force main downstream of the leaking connection and noted readings in excess of 110 psi (beyond the service rating of the pipeline), indicating that a blockage had formed in the downstream 24-inch force main. With both the 18-inch and 24-inch force mains out of service, an emergency temporary relief discharge pipe was installed to direct the overflow into Trout Creek and relieve pressure in the force mains llowing the pump stations in the area to begin pumping down the surcharged collection system to mitigate the increasing risk of overflows in multiple residential areas. Wastewater crews in conjunction with the contractor hired by the Department replaced the damaged section of 18-inch force main near the end of the northbound off ramp from I-75 so that it could be returned to service, ceasing the overflow into Trout Creek at 4:45 PM on Thursday, March 17, The temporary bypass around the apparent broken section of pipe was used to maintain service until the leaking connection near Richmond Place was replaced. Where Did the Overflow Go?: The initial overflow from the damaged section of 18-inch force main near the end of the northbound off ramp from I-75 (estimated at 1.8 million gallons) accumulated and was contained in the ditch on the northeast side of the northbound off ramp from I-75 and adjacent wooded area. Crews were able to vacuum approximately 69,000 gallons of effluent from the ditch and return it to the collection system downstream of the break. In addition, approximately 3.0 million gallons of mixed groundwater and effluent was pumped out of the adjacent wooded area and returned to the collection system once the 18- inch force main was returned to service. The secondary overflow (approximately 4 million gallons) discharged directly into Trout Creek, which flows south to the Hillsborough River. Department personnel have been sampling water along Trout Creek and the Hillsborough River and posting signs at access points to the Hillsborough River warning of possible high bacteria levels. Testing will continue until the contamination levels return to background levels for swimming, wading, or fishing. Steps Taken or Planned to Reduce, Eliminate, and Prevent Recurrence:

3 Page 3 / 7 The Wastewater Department has entered into a Joint Project Agreement with Hillsborough County to install a new 30-inch force main in Bruce B. Downs Boulevard as part of the ongoing widening project. Once the new pipeline is installed both the existing 18-inch and 24-inch force mains will be taken out of service and ultimately removed. To better protect the existing force mains for the remainder of the roadway widening project, rather than relying upon as-built drawings or trenchless locating techniques, Wastewater Department personnel will be performing multiple vacuum excavations to physically locate and mark both of the existing force mains at regular intervals throughout the entire project limits. Crews will also be installing additional pressure gauges along the 24-inch force main to better locate the blockage and determine if it can be removed prior to 24-inch force main being permanently taken out of service.

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