HOW OUR REGION CAN WORK TOGETHER FOR CLEAN WATER Technical Report August 2015 Technical Report 1.0 Introduction ……………………………………………………………………...1-1 2.0 Source Control Practices Section Summary ........................................................................................................ 2-1 2.1 Green Stormwater Infrastructure ....................................................................... 2-2 2.1.1 Benefits of Green Stormwater Infrastructure .......................................... 2-2 2.1.2 National and Regional Perspectives on Controlling CSOs through Green Stormwater Infrastructure ................................................................................ 2-4 2.1.3 Current Green Stormwater Infrastructure in the Pittsburgh Region ..... 2-9 2.2 Inflow and Infiltration (I/I) Source Reduction ................................................... 2-11 2.2.1 What is Inflow and Infiltration Source Reduction? ................................ 2-11 2.2.2 Benefits of I/I Reduction .......................................................................... 2-12 2.2.3 National and Regional Perspectives on I/I Reduction ............................ 2-12 2.3 Source Control in Municipal Feasibility Studies ............................................... 2-16 3.0 Regional Source Control Analysis Section Summary ........................................................................................................ 3-1 3.1 Source Control Performance and Costs ............................................................... 3-3 3.1.1 Green Stormwater Infrastructure............................................................. 3-3 3.1.2 I/I Reduction ............................................................................................ 3-18 3.2 Benefits and Cost-Effectiveness of Large-Scale Source Control Implementation ........................................................................................................ 3-23 3.2.1 Green Stormwater Infrastructure........................................................... 3-23 3.2.2 I/I Reduction ............................................................................................ 3-26 3.2.3 Combination of GSI and I/I Reduction .................................................... 3-30 3.3 Opportunities to Eliminate Traditional Infrastructure in the Selected Plan .. 3-35 3.3.1 Green Stormwater Infrastructure........................................................... 3-37 3.3.2 I/I Reduction ............................................................................................ 3-44 3.3.3 Sewer Separation .................................................................................... 3-52 3.3.4 Direct Stream Inflows ............................................................................. 3-54 3.4 Opportunities to Downsize Traditional Infrastructure in the Selected Plan ... 3-57 3.4.1 Regional Tunnel and Pump Station Downsizing .................................... 3-58 3.4.2 Regional Conveyance and Municipal Pipe Downsizing .......................... 3-61 i 3.4.3 Cost Analysis ........................................................................................... 3-61 4.0 Municipal Opportunity Assessment & Potential Projects Section Summary ........................................................................................................ 4-1 4.1 Municipal Green Infrastructure Analyses .......................................................... 4-2 4.1.1 ALCOSAN Regional Source Control Analysis .......................................... 4-2 4.1.2 3RWW Green Infrastructure Project Identification ................................. 4-2 4.1.3 Lawrenceville Green Infrastructure Pilot Study Area ............................. 4-8 4.1.4 Other Green Stormwater Infrastructure Analyses in the ALCOSAN Service Area ..................................................................................................... 4-11 4.2 Municipal Coordination and Identification of Potential Green Infrastructure Projects ..................................................................................................................... 4-17 4.2.1 Municipality and Stakeholder Meetings ................................................. 4-17 4.2.2 Identification of Potential GSI Opportunities ........................................ 4-17 4.3 Assessment of Potential Green Infrastructure Project Opportunities ............ 4-21 4.4 Concepts for Example Green Infrastructure Projects ....................................... 4-23 4.4.1 Braddock Borough Community Plaza………..……………………………. 4-23 4.4.2 Homestead Borough Frick Park Infiltration Trenches .......................... 4-25 4.4.3 City of Pittsburgh Beltzhoover Neighborhood – McKinley Park GSI .... 4-26 4.4.4 Etna Borough GSI Concept from Etna Green Infrastructure Master Plan ...................................................................................................... 4-28 4.4.5 Project 15206 GSI Concept in the City of Pittsburgh, Morningside Neighborhood ................................................................................................... 4-30 4.4.6 East Pittsburgh Grandview Avenue Park, East Pittsburgh Borough ... 4-31 4.4.7 ALCOSAN Access Shaft M-30 Property, City of Pittsburgh Greenfield Neighborhood ................................................................................................... 4-32 4.4.8 Fleming Avenue GSI and Community Park, Stowe Township .............. 4-33 4.4.9 Allegheny Commons North Avenue GSI Concept, City of Pittsburgh ... 4-34 4.4.10 Airbrake Avenue Trail GSI Concept, Wilmerding Borough ................. 4-35 4.5 Potential Municipal I/I Reduction Projects ...................................................... 4-36 4.5.1 Municipal Meetings ............................................................................... 4-36 4.5.2 Identification of Potential I/I Reduction Opportunities ......................... 4-37 4.6 ALCOSAN Partnership Opportunities ............................................................. 4-37 ii 5.0 A Greener Wet Weather Strategy Section Summary ........................................................................................................ 5-1 5.1 Abundant Opportunities ...................................................................................... 5-2 5.2 A Greener Alternative......................................................................................... 5-13 6.0 Source Reduction Incentives Section Summary ........................................................................................................ 6-1 6.1 Wet Weather Charges .......................................................................................... 6-3 6.2 Green Stormwater Incentive Programs .............................................................. 6-6 6.3 Inflow and Infiltration Source Reduction Incentives ........................................... 6-9 6.4 ALCOSAN Legal and Institutional Context ...................................................... 6-11 6.5 ALCOSAN Incentives Program Options ............................................................ 6-12 6.6 Analysis of Options ............................................................................................. 6-24 7.0 ALCOSAN’s Flow Reduction Program……………………...7-1 iii Report Appendices A. Approaches and Perspectives on GSI and Other Source Controls B. GSI Installations in the ALCOSAN Service Area C. GSI Cost Literature Review D. Inflow and Infiltration Reduction in Sanitary Sewers E. 3RWW GSI Project Identification Report F. Lawrenceville GSI Pilot Study G. Municipality and Stakeholder Outreach H. Project Location Site Summaries I. Select GSI Projects iv List of Figures Section 1 Figures Figure 1-1 Four Categories of Sewer Overflow Control Technologies ........................... 1-1 Section 2 Figures Figure 2-1 ALCOSAN Design Rendering for McKinley Park in the Beltzhoover Neighborhood of Pittsburgh ............................................................................................ 2-3 Figure 2-2 Pathways of Infiltration and Inflow (I/I) into Sanitary Sewer Systems and Various I/I Investigation Tools .............................................................................. 2-11 Section 3 Figures Figure 3-1 Example of System Wet Weather Treatment and Dewatering Capacity .... 3-5 Figure 3-2 Cumulative Distribution of Rainfall Event Volumes ................................... 3-8 Figure 3-3 Cumulative Distribution of Saturated Vertical Hydraulic Conductivity Assumptions in Hydrologic Models used in the WWP ................................................... 3-9 Figure 3-4 Illustration of Loading Ratio Definition ..................................................... 3-10 Figure 3-5 GSI Redevelopment Example: ALCOSAN Customer Service Building ..... 3-14 Figure 3-6 GSI Retrofit Example: Local 95 Operating Engineers Union Building on Saline Street ............................................................................................................. 3-14 Figure 3-7 National Comparison – Construction Cost ($ per Square Foot) of Installed GSI ................................................................................................................. 3-14 Figure 3-8 National Comparison – Capital Cost ($ per Square Foot) of Installed GSI ................................................................................................................................. 3-15 Figure 3-9 Potential Value of Development/Redevelopment Ordinances ...................