WASHINGTON SUBURBAN SANITARY COMMISSION OVERFLOW WRITTEN REPORT

2984373-118-2020

MDE OFFICIAL CONTACTED: EBONY PARRIS DATA CALLED IN BY: KEVIN VERRETT DATE: 08/04/2020 AT 12:50PM

WORK ORDER(S): 2984373 2984365

EST DATE AND TIME SSO BEGAN: 08/04/2020 10:36AM DURATION: 16.90 HRS DATE AND TIME SSO ENDED: 08/05/2020 03:30AM

SOURCE-OVERFLOWING MH MH04001003, 04001011, 04001006 & 04043002 WATER BODY AFFECTED-PISCATAWAY CREEK CLOSEST STREET ADDRESS: 14313 INDIAN HEAD HWY 20607 COUNTY/PAGE/GRID: P 5881 B09 TOWN/CITY: ACCOKEEK

CAUSE: EXCESS FLOW EST OVERFLOW VOLUME: 102,927 GAL WSSC WATER PERSONNEL OBSERVED 003U (30 GPM) AND 011U (0.5 GPM) NEAR THE PISCATAWAY WATER RESOURCE RECOVERY FACILITY OVERFLOWING A COMBINED RATE OF 30.5 GPM DURING HEAVY RAINS FROM TROPICAL STORM ISAIAS. THE PISCATAWAY RAW HAD EXCEEDED ITS CAPACITY, CAUSING THE COLLECTION SYSTEM TO SURCHARGE. ONCE THE EXCESS FLOW SUBSIDED, THE EVENT ENDED.

IMPACTS UPON PUBLIC HEALTH AND STATE WATERS: DISCOLORATION NOTICEABLE ODOR PUBLIC ACCESS PUBLIC USE OBSERVED VISIBLE SOLIDS, STREAM BANK VISIBLE SOLIDS, IN STREAM WET WEATHER DILUTED SEWAGE, SOLIDS AND RAGS ENTERED PISCATAWAY CREEK IN THE PISCATAWAY CREEK BASIN.

STEPS TAKEN OR PLANNED TO REDUCE, ELIMINATE AND PREVENT RECURRENCE: THE PROBLEM WITH THIS SEWER LINE HAS BEEN REFERRED TO LINE BLOCKAGE ANALYSIS (LBA) FOR REVIEW. A FOLLOW-UP INVESTIGATION WILL BE CONDUC- TED TO DETERMINE WHAT MEASURES SHOULD BE TAKEN TO REDUCE OR ELIMINATE THE CHANCE OF THIS LINE OVERFLOWING AGAIN. ***** THE MANHOLES ARE INACCESSIBLE (LAST MANHOLES BEFORE THE PISCATAWAY WATER RESOURCE RECOVERY FACILITY, AND THE MAINS ARE 42 INCHES (003U) AND 36 INCHES (011U)); THEREFORE, THESE LINES ARE NOT CCTVABLE. ***** 08/13/2020 UPDATE - WSSC WATER'S TRUNK WALK PROGRAM CONSULTANT HAS A TRAIL CAMERA INSTALLED AT MANHOLES 006M AND 002M DUE TO ASSETS LOCATED IN DEEP RIGHT-OF-WAY WITH LIMITED ACCESS DURING HEAVY RAIN EVENTS. THE CONSULTANT WAS ABLE TO RETRIEVE THE VIDEO DATA ON 08/11/2020, CONFIRMING MANHOLES 006M (24,600 GALS) AND 002M (47,400 GALS) OVERFLOWED. THE COMBINED TOTAL ESTIMATED OVERFLOW IS 102,927 GALLONS. MANHOLES 006M AND 002M ARE INACCESSIBLE AND, THEREFORE, NOT CCTVABLE.

MEASURES INITIATED/TAKEN TO MINIMIZE IMPACT: LIME RAKED AREA VISIBLE SOLIDS REMOVED

NOTIFICATIONS MADE: MD DEPARTMENT OF ENVIRONMENT PG COUNTY HEALTH DEPT PG COUNTY MUNICIPALITIES NEWSPAPER RADIO STATIONS TELEVISION MEDIA ADVISORY ISSUED ON 08/04/2020.

SIGNS POSTED: 4 POST DATE: 08/04/2020