Municipal Separate Storm Sewer Systems
Multiple Municipalities, Allegheny County, PA

PWet Weather Plan

Urban Sewershed Wet Weather Plan Demonstration Project
Nine Mile Run, Allegheny County, PA

Martinsburg WWTP

Wastewater Treatment Plant
Martinsburg, Blair County, PA


Infiltration / Inflow (I/I) and Source
Flow Reduction


Lennon, Smith, Souleret Engineering (LSSE) provides services for sewer system analysis, I/I quantification and flow isolation, design, permitting and construction observation of Infiltration / Inflow (I/I) projects in municipal sewer systems.

LSSE's recent experience includes performing SSES and related I/I investigations, flow monitoring and hydraulic modeling. A recent I/I mitigation project resulted in elimination of 50% of the measured I/I by replacing approximately 10% of existing sanitary sewers (installation of a new parallel sanitary sewer system up to individual basements and conversion of the existing sewers to a dedicated groundwater underdrain).

Services include:

  • Flow monitoring
  • Flow isolation studies
  • Present worth based cost effectiveness analysis
  • Design
  • Permitting and implementation
  • Post project certification
  • Hydraulic and hydrologic modeling / analysis
  • Partial Parallel Replacement to eliminate SSO's and achieve significant RD I/I and GWI flow reduction
  • RTK analytic parameters to be put into SWMM models to assess pipe capacity analysis