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Dennis Catanyag [EH] From: Mark Zollo [mzollo@lodi.gov] Sent: Monday, March 21, 2005 3:47 PM To: Dennis Catanyag [EH] Cc: Richard Prima; Dennis Callahan; Roger D. Rich; Ronald Bianchetti (E-mail) Subject: City of Lodi. 1331 S. Ham Ln., Cathodic Testing of 10K Gallon Unleaded Tank A ~JI RiserDetail.JPG D-A6Die1ec.JPG WasteONSump.JPG Un1eadSump2.JPG Un1eadSump1.JPG Dennis, Per your request: Regarding: 10,000 gallon unleaded tank cathodic protection (CP) system deficiency investigation. This summary begins from the engineer's (R. Bianchetti) and EHD's (D. Catanyag) <<RiserDetail.JPG>> <<D-A6Dielec.JPG>> <<WasteOilSump.JPG>> <<UnleadSump2.JPG>> <<UnleadSumpl.JPG>> last visit to the 1331 S. Ham Lane site on 3/4/05. At that time, Mr. Bianchetti detected continuity between the unleaded tank's cathodic system, the building's electrical system, and the Compressed natural gas (CNG) system, including the CNG's cathodic system. City of Lodi staff ordered a reference anode necessary for testing and spent last week investigating the various systems to locate the interconnection. This process turned out to be a bit tricky, but easily remedied. First, the as built plans from 1988 (D-A6Dielec.JPG & RiserDetail.JPG) indicate that both risers in the unleaded sump have dielectric fittings. One of the risers in the sump is the pump and the other was originally a mechanical tank fuel level gauge device. During the CNG project, the dispensers, the 10K gallon unleaded tank and the adjacent 2K gallon unleaded tank received upgrades and modifications. One of the modifications connected the two tanks by fiberglass piping using the riser that housed the mechanical tank level gauge (Tank level is measured electronically) . A copper line connected to the pump housing utilizes vacuum created during pump operation to maintain a siphon between the tanks. Although the risers did not share continuity, we were unable to ascertain which of the risers connected to the tank without a dielectric fitting since we could not test between the tank body and the risers. A review of file information by the Steel Tank Institute provided a simple method to positively test continuity between the tank and the risers by attaching a screw with a wire lead to the end of the tank gauge stick. The stick is dropped into the interstitial space of the tank and contacts the tank's metal interior. A Lodi Electric Utility (LEU) technician determined that the pump riser was insulated from the tank by a dielectric fitting and that the siphon riser was not. This determination indicated two problems with the CP system. First, The CP system was connected (clamped) to the fuel pump riser. Second, the two risers were electrically connected by the copper siphon line. The solution was to move the CP system clamp to the siphon riser, which is directly connected to the tank and to use non-conductive tubing for the siphon line (UnLeadSumpl.JPG & UnLeadSump2.JPG) . These two changes isolate the pump's electrical system from the tank and the tank's CP system. Readings by the LEU technician showed immediate and satisfactory CP system performance. This faulty configuration of the 10K gallon unleaded tank CP system was the interconnection that Mr. Bianchetti detected on his last visit and is due to work performed by Stockton Service Station Equipment Co. in the course of the CNG project (1/02 through 12/02) , not a long term deficiency with the CP system. Mr. Bianchetti has tentatively scheduled this Friday to perform the retest of the 10K tank and begin some work on the CNG CP system. If the tank test satisfactorily, which I expect, I would estimate a finished report within a week (+/-) . The last image shows the installed test board for the waste oil tank (WasteOilSump.JPG) , which corrected the problem with that tank's CP system. 1