NIAGARA MOHAWK POWER CORP — Gas transmission and gathering — incident on 2013-07-03

Gas transmission and gathering incident in SHERRILL, ONEIDA County, NY. Reported cause: NATURAL FORCE DAMAGE. Reported consequences: 0 fatalities, 0 injuries, 2900 NATURAL GAS released, $651,500 reported property damage. Operator-reported incident data submitted to PHMSA, generally within 30 days. Records may be supplemented or corrected and do not represent final agency causal findings.

Report number: 20130074.

Operator ID: 13480.

Reported incident date: 7/3/2013 14:56.

Location detail: SCONONDOA CRK

Cause detail: HEAVY RAINS/FLOODS

Cause detail: EXTREME RAINFALL IN THE MOHAWK VALLEY REGION OF UPSTATE NY CAUSED LOCALIZED FLOODING NEAR THE MOHAWK RIVER AND ASSOCIATED TRIBUTARIES. IN THE TOWNSHIP OF SHERRIL, THE SCONONDOA CREEK OVER-TOPPED IT'S BANKS NEAR THE STERLING POWER GENERATING PLANT. THE ASSOCIATED FLOODING AND STRONG CURRENTS ERODED THE COVER FROM PIPELINE 61, A 6" 473 PSI MAOP PIPELINE SERVING ONLY STERLING POWER. FLOOD WATER INUNDATED THE POWER GENERATING PLANT AND PROMPTED A PRE-EMPTIVE SHUT DOWN OF PIPELINE 61. THE PIPELINE DEPRESSURIZED UNDER THE SUPERVISION OF LOCAL OPERATING PERSONNEL. SUBSEQUENT TO THE WEATHER EVENT, FLOODWATERS RECEDED AND REVEALED THAT PIPELINE 61 HAD BEEN COMPROMISED IN THE MAIN STREAM BED. NOTE: PART A, 15A: PIPELINE WAS SHUT DOWN AS A PRECAUTION ON 06/28/13 DUE TO FLOODING CONDITIONS. PART C, 3G: DATE OF MANUFACTURER IS BASED ON PURCHASE ORDER DATE OF 10/02/90.

PHMSA trend classification: significant incident, not serious.

PHMSA standardized cause: NATURAL FORCE DAMAGE — HEAVY RAINS/FLOODS.

PHMSA indexed costs: $662,973 reported total cost, $345,972.702 in 1984 dollars, $841,556.363 in current-year dollars.

PHMSA trend flags, standardized causes, and indexed costs are analytical fields added to operator-reported incident data. They do not represent final agency causal findings.