It likely deserves a New Word already; I propose: SHITASTROPHE – 900 million gallons of raw sewage spewed to-date with no end in sight in an unimaginably damaging catatrophe, the largest ever in American (and possibly world) history. It’s already 90 times worse than Exxon Valdez. Most local residents have never even heard not one peep about it!
Assuming you mean the Potomac Interceptor (PI) (the large sanitary sewer line tied to the recent Potomac sewage incident), here are the direct answers.
Who owns it?
Operationally, the PI system is under DC Water (legal name: District of Columbia Water and Sewer Authority / DCWASA). The project documents state DCWASA is responsible for operation/maintenance of the PI except the Maryland Upper Potomac Interceptor (MUPI) segment, which is operated/maintained by WSSC Water.
Where does it come from and go to, exactly?
Public engineering docs describe this flow path:
- Wastewater originates in service areas near Dulles Airport (plus Fairfax, Loudoun, Montgomery, DC, and certain local jurisdictions/entities feeding in).
- It moves through the PI system segments (PI trunk / MUPI / UPI / UPIRS).
- It reaches the Potomac Pumping Station in Washington, DC.
- From there it is pumped to Blue Plains Advanced Wastewater Treatment Plant.
- After treatment, discharge is to the Potomac.
Segment-level detail in the EA: PI trunk includes Sugarland Run, Difficult Run, and Upper Maryland Spur; MUPI feeds UPI at the DC line; UPI feeds UPIRS; UPIRS goes to Potomac Pump Station.
Under-river detail: the PI has two river tunnel crossings, with the longest noted as about 3,000 ft beneath the Potomac near Great Falls/Washington Aqueduct area. (DC Water)
When was it built?
- Authorized by Public Law 86-515 on June 12, 1960.
- DC Water materials indicate first flows began in 1964 (i.e., construction/commissioning in the 1960s). (DC Water)
Who has the engineering blueprints?
For current “record” drawings and official engineering files:
- DC Water: their CAD/records standards state final as-built drawings are submitted to DC Water, then linked in GIS and stored in their enterprise document system (OpenText/Livelink) for long-term records. (DC Water)
- WSSC Water (for its MUPI/related assets): WSSC’s WERI system maintains scanned engineering documents/plans/finals and GIS layers, with controlled access. (wsscwater.com)
Historically, legacy design reports also exist from engineering consultants (e.g., Burns & McDonnell 1961 reference in PI EA), but official as-built/control copies are held by the utilities above.
(Past chat)(Past chat)(Past chat)(Past chat)
Perfect — here’s the segment-level chain in upstream-to-downstream order.
Potomac Interceptor flow chain (as published)
Branch A (Virginia / Dulles side):
Areas near Dulles feed the PI main trunk (subsystems: Difficult Run Extension (200 series), Sugarland Run Extension (300 series), Upper Maryland Spur (400 series)). (DC Water)
Branch B (Montgomery County side):
Montgomery County wastewater enters the MUPI (3000 series), which feeds the UPI (2900 series) at the DC line.
Convergence in DC:
The UPI conveys flow to UPIRS (1900 series), and UPIRS carries flow (including PI main trunk contributions and other service connections) to the Potomac Pump Station in Washington, DC.
Final destination:
From Potomac Pump Station, flow is sent to Blue Plains Advanced Wastewater Treatment Plant, then discharged to the Potomac after treatment. (DC Water)
Ownership / control (operational)
- DC Water operates and maintains the PI system overall.
- Exception: MUPI is operated/maintained by WSSC Water.
Build era
- Authorized by Public Law 86-515 (June 12, 1960).
- First sewage flows are documented as beginning in 1964. (DC Water)
Physical scale markers
- System is shown as 54+ miles, with 11 tunnel sections and 2 river tunnel crossings in current DC Water fact material.
- Great Falls crossing is identified as a 3,000-foot segment and 78-inch sewer line. (DC Water)
Who has the blueprints / engineering records
- DC Water holds modern record-drawing submissions in its enterprise records workflow (GIS updates + OpenText/Livelink archival).
- WSSC Water holds its engineering records via WERI (plans/finals/house connections/200’ sheets, etc.). (wsscwater.com)
- Public-facing DC Water request channels provide GIS/counter-map infrastructure info (pipe location/structures), while full detailed plan access is handled through utility records processes. (DC Water)
Next pass is a records-request packet (DC Water + WSSC) specifically asking for:
- PI/MUPI/UPI/UPIRS as-builts,
- plan-and-profile sheets by structure series,
- latest rehab design set for the Potomac River crossing segment.