6/25/2012. Overview. DC Combined Sewer System. Greening of DC Water s Infrastructure: Balancing Mandates, LID Options, and Stakeholder Interests

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1 District of Columbia Water and Sewer Authority George S. Hawkins, General Manager Briefing on: Greening of DC Water s Infrastructure: Balancing Mandates, LID Options, and Stakeholder Interests Briefing for: APWA Sustainability Conference 2012 June 26, Overview DC Clean Rivers Project Background Consent Decree Requirements Proposed LID Practices Maintenance Requirements Proposed LID Measures at Each Site Monitoring Schedule DC Water Green Infrastructure 2 DC Combined Sewer System 1/3 of DC area is served by combined sewers (12,478 acres) 53 CSO outfalls 15 to Anacostia 10 to Potomac 28 to Rock Creek Three receiving waters Anacostia River Potomac River Rock Creek 3 1

2 What is a CSO? 100% of Suburbs 67% of DC 0% of suburbs 33% of DC 4 4 LTCP Development Timeline Public Participation Current: DC Water implementing LTCP 5 5 LUZON VALLEY (SEPARATED) GREEN INFRASTRUCTURE (MULTIPLE SITES THROUGHOUT DISTRICT) DC CLEAN RIVERS PROJECT AND NITROGEN REMOVAL PROGRAMS COMBINED SEWER AREA ROCK CREEK TUNNEL SEPARATE CSO 031, 037, 053 AND 058 ROCK CREEK REGULATOR ADJUSTMENTS CSO 033, 036 AND 057 F F NORTHEAST BOUNDARY TUNNEL POTOMAC TUNNEL WHITE HOUSE REHAB POTOMAC P.S. P U.S. CAPITOL RFK P ABANDON NORTHEAST BOUNDARY SWIRL DC CLEAN RIVERS PROJECT: $2.6 BILLION NITROGEN REMOVAL: $950 MILLION TOTAL > $ 3 BILLION 20 YR IMPLEMENTATION ( ) 96% REDUCTION IN CSO FLOOD RELIEF IN NORTHEAST BOUNDARY MAIN PS P P P ANACOSTIA RIVER TUNNEL SEPARATE CSO 006 REPLACE POPLAR POINT P.S. BLUE PLAINS TUNNEL P F PUMP STATION KNOWN FLOODING AREA BLUE PLAINS P ENHANCED CLARIFICATION TREATMENT & NITROGEN REMOVAL AT BLUE PLAINS 6 TUNNEL DEWATERING P.S. 6 2

3 Benefits of DC Clean Rivers Project 1 CSO Reduction Item Anacostia River Potomac River Rock Creek Total CSO Overflow Volume (mg/avg yr) 1996 DC Water Formed 2,142 1, , DCCR in Place % Reduction 98% 93% 90% 96% 2 Water Quality Improvement Bacteria levels will be lower, dissolved oxygen will be higher 3 Trash Reduction Trash from CSOs will be practically eliminated 7 4 Flooding Relief in Northeast Boundary Area Improves property values Supports economic development Protects private and public property Less impact of DDOT roads during rain events Less need for emergency response/rescues during rain events 7 DC Clean Rivers Project Schedule Consent Decree Requirements Principal Consent Decree Milestones for Anacostia River CSO Control Projects Consent Decree Effective March 23, 2005 Submit Facility Plan (Complete) September 23, 2008 Start Design (Complete) March 23, 2009 Start Construction (Complete)* March 23, 2012 Place in Operation River Area Tunnels (South of RFK Stadium) Northeast Boundary Area Tunnels (North of RFK Stadium) March 23, 2018 March 23, 2025 * Construction began in February 2010 with the Division W Blue Plains Tunnel Site Preparation Contract 8 8 Implementation Status Anacostia River Projects Construct storage/conveyance Tunnel 23-ft inside diameter 157 million gallons of storage Construct Diversion Sewers to collect and direct flow to the Tunnel (i.e. M Street Diversion Sewer) Program on schedule, within budget Place facilities south of RFK stadium in operation by 2018, remainder by 2025 Project required by Federal Consent Decree Stipulated penalties for failure to meet specified schedules Northeast Boundary Branch Tunnel (Planning) Tingey St Diversions (Procurement) Main PS Diversions (Design) Poplar Point PS (Design) 9 Northeast Boundary Tunnel (Planning) M St Div. Sewer (Construction) CSO 019 (Construction) Anacostia River Tun. (Procurement) CSO 007 (Construction) Blue Plains Tunnel (Construction) A Blue Plains Tunnel C CSO 019 Overflow and Diversion Structures D JBAB Overflow and Potomac Outfall Sewer Diversion E M Street Diversion Sewer (CSOs 015, 016 and 017) G CSO 007 Diversion Structure and Diversion Sewer H Anacostia River Tunnel I Main Pumping Station and Tingey Street Diversions J Northeast Boundary Tunnel K Northeast Boundary Branch Tunnels L Northeast Boundary Diversions M Mt. Olivet Road Diversions Y Blue Plains Dewatering 9 Pumping Station and ECF 9 Z Poplar Point Pumping Station Replacement W Blue Plains Tunnel Site Preparation 3

4 LID Consent Decree Requirements DC Water shall incorporate LIDR techniques into new construction or reconstruction on DC Water facilities for demonstration projects up to a total expenditure of $3 million and shall maintain the LIDR projects for at least five (5) years after each project is Placed into Operation. United States District Court Consolidated Civil Action No. 1:CV00183TFH, page 27 March 23, 2005 # Activity CD Deadline Actual 1 Submit Plan for DCW Facilities 2 DCW Submitted updated Plan for DCW facilities 3/23/2007 3/23/2007 (EPA approved 3/18/2008) Not Required Submitted 1/2010 (EPA approved 11/4/2010) 3 Place Facilities in operation 3/18/ Perform min 12 months of monitoring 5 Submit Project Analysis Report 6 End of Period for DCW to Maintain LID Facilities 3/18/ /18/ /18/ Work Completed at Bryant Street and Eastside Pumping Stations LID Installed at Bryant St PS DC WASA Property Line Revegetated Hillside s LID Installed at Eastside PS Permeable Paveme nt Filterra tree box 11 Additional LID Site Locations Facility Anacostia Water Pump Station Address th Street SE Washington DC, East Side Pumping Station 2600 Independence Ave SE Washington DC, Fort Reno Reservoir 3900 Donaldson Place NW Washington DC,

5 DC Water Facilities Sites Evaluated for LID Facility Potomac Pump Station Upper Anacostia Pump Station Earl Place Pump Station Rock Creek Pump Station Brentwood Reservoir Bryant Street Pump Station Main and O Street Pump Station Stormwater Pump Station Blue Plains WWTP Fort Stanton Reasoning for Rejection Construction Project; Limited DC Water control of site. Recently renovated; Small site. Small site. Recently renovated; Small site. Future site disturbance. LID already completed. Major construction; Land ownership issue. Maintenance responsibility unclear. Ongoing major construction; Stormwater treated in plant. Storage tank leakage issues. Unknown rehab schedule. 13 Proposed LID Practices BIORETENTION AREA Captures surface runoff in a shallow, vegetated depression underlain with a permeable soil medium. PERVIOUS PAVEMENT Permits percolation of surface runoff through a permeable media (concrete, asphalt, or pavers) into a gravel subgrade. VEGETATED FILTER STRIP Filters runoff before entering a bioretention area. GREEN ROOF Intercepts rainfall via a growing medium and vegetation on a roof. STORMWATER TREATMENT SYSTEM Filters stormwater downstream of the proposed storm drains. STONE DIAPHRAGM Filters runoff before discharging into a bioretention Area. 14 Post-installation Maintenance BIORETENTION AREA Every 6 months: Inspect mulch/vegetation Each year: Inspect underdrain for clogging or failure; replace mulch As required: Replace dead vegetation PERVIOUS PAVEMENT Every 4-6 months: Vacuum surface (or every 3 months if sediment/debris is present) VEGETATED FILTER STRIP Each year: Inspect vegetation As required: Replace dead vegetation. GREEN ROOF Each month: Inspect irrigation (for first 2 years) and weed As required: Trim vegetation, remove and replace dead vegetation. STORM WATER TREATMENT SYSTEM Twice a year: Inspect condition of system. As required: Vacuum sediment out of unit, (when sediment level Reaches inches below dry weather water surface elev.) STONE DIAPHRAGM Each month: Remove surface debris Source: Adopted from Northern Virginia BMP Handbook, Low Impact Development Supplement, October 2007, Revised November CURRENT PLAN IS TO CONTRACT MAINTENANCE FOR FIRST 5 YEARS REQUIRE BY CD, THEN DC WATER CAN DECIDE FUTURE MAINTENANCE PLAN 15 5

6 Anacostia Water Pumping Station Existing Site Conditions Front Entrance to Pumping Station Existing Bioretention Cell 16 Anacostia Water Pump Station Proposed LID Retrofit Improvements BIORETENTION AREA #1 (610 SF) BIORETENTION AREA #3 (733 SF) Dark blue arrows indicate the direction of surface runoff into the LID practices. VEGETATED FILTER STRIP (340 SF) PERMEABLE PAVEMENT (1152 SF) BIORETENTION AREA #2 (219 SF) BIORETENTION AREA #1: Captures runoff from majority of existing impervious parking areas. BIORETENTION AREA #2: Captures portion of roof runoff. VEGETATED FILTER STRIP: Filters debris from runoff before it enters Bioretention Area #1. BIORETENTION AREA #3: Captures portion of roof runoff; controlled by culvert inlet at south end. Suggest replacement of existing soils to fix anaerobic (wetland) condition, if budget allows. PERVIOUS PAVEMENT: Captures runoff from majority of parking areas. 17 East Side Pumping Station Existing Site Conditions Existing Pumping Station Existing Roof (facing North) 18 6

7 East Side Pumping Station Proposed LID Retrofit Improvements REPAVE LOT CONCRETE TO REPLACE PERVIOUS PAVEMENT Dark blue arrows indicate the direction of surface runoff into the LID practices. STONE DIAPHRAGM STORMWATER TREATMENT SYSTEM BIORETENTION AREA (2,041 SF) GREEN ROOF (3,865 SF) STONE DIAPHRAGM: Filters debris from runoff before it enters Bioretention Area. BIORETENTION AREA: Captures runoff from adjacent parking areas and driveway after being filtered by the Stone Diaphragm. GREEN ROOF: Roof captures precipitation on East Side Pumping Station. STORMWATER TREATMENT SYSTEM: Filters stormwater downstream of the proposed storm drains. NOTE: Deteriorated pervious pavers in existing parking area to be replaced with concrete. 19 East Side Pump Station Proposed Green Roof Structural Analysis indicates: If existing roofing (insulation and waterproofing) is retained, allowable load is 50 psf for green roof system Proposed Green Roof design: 3-5 depth Planted with sedums and succulents Maintenance: Monthly: Inspect irrigation (first 2 years) and maintain As required: Trim vegetation, remove and replace dead vegetation Constructed without interruption of pump station service Roof screens and HVAC equipment will not be impacted and paver paths provided for accessibility Existing East Side Pumping Station Roof 20 East Side Pumping Station Proposed Green Roof Rendering 21 7

8 Fort Reno Reservoir and Pumping Station Existing Site Conditions Fort Reno Pumping Station Roof Fort Reno Reservoir Roof 22 Fort Reno Reservoir Proposed LID Retrofit Improvements PERVIOUS PAVEMENT: Captures runoff from majority of parking areas. Move trailer office completely off parking area to the east (~50 ). GREEN ROOF: Roof captures precipitation on Reservoir roof. Deteriorated asphalt perimeter ditches (850 LF) to be replaced with concrete. PERVIOUS PAVEMENT (8,790 SF) GREEN ROOF (1,830 SF) Dark blue arrows indicate the direction of surface runoff into the LID practices. GREEN ROOF (39,090 SF) TRAILER OFFICE PERIMETER DITCH 23 Fort Reno Reservoir Proposed Green Roof April 2010 inspection report indicates: Generally good condition, no structural deficiencies New roof system installed in 2000 Preliminary Structural Analysis indicates: Available loading of 50 psf for plants, foam board insulation, and planting media acceptable Recommended concrete sampling cores to confirm structural conditions Proposed Green Roof Design: 3-5 depth Planted with sedums and succulents Maintenance Monthly: Inspect irrigation first 2 years and weed As required: Trim vegetation, remove and replace dead vegetation Constructed without interruption of reservoir service and operation Access hatches and ventilation houses will not be impacted. Paver paths provided for accessibility EXISTING RESERVOIR ROOF: Roofing material Foam board insulation Lightweight concrete Concrete slab roof Reservoir wall PROPOSED GREEN ROOF: Green Roof media and vegetation Drainage layer Membrane & root barrier Foam board insulation Concrete slab roof Reservoir wall 24 8

9 Fort Reno Reservoir Proposed Green Roof Rendering 25 Pre- & Post-installation Monitoring Pre-Improvement Monitoring Install rain gauge at each site to estimate runoff Install meters where feasible (some sites will need to be modeled) Post-Improvement Monitoring Install outlet weir or Parshall flume for continuous volume monitoring at each site Setup/Install manhole to collect grab samples (with option for continuous sampling of TSS, TN and TP) at each site Installation of monitoring equipment will not impact operations Site access for installation and maintenance of equipment will be needed Rain gauge installed at Wetlands Studies Solutions, Inc. 26 Proposed Schedule No. Activity Start Finish Duration (months) 1 Meet Operations Staff By 1/13/ Finish Design to 95% (Prefinal) 2/1/2012 6/1/ Bid Advertisement 9/10/ /10/ Award Contract -- 1/11/ Construction 1/11/ /31/ Place in operation -- 3/18/ CD Deadline -- 3/18/

10 Impact of Existing Construction on Schedule East Side, Anacostia, (in no particular order) LID Retrofit Project Construction Fort Reno Anacostia Pump Station None CSO 19 Diversion Chamber and Overflow Structure East Side Pump Station Fort Reno Reservoir Water Distribution Rehab 28 Proposed DC Water Green Infrastructure Existing facilities at Blue Plains Advanced Wastewater Treatement Plant Public and Private space in the Rock Creek River and Potomac River Tunnel Drainage Basins Typical low-med density residential Typical Georgetown historical area Typical high density Proposed Green Infrastructure in the District 29 Contact Information Anthony Laufik Address: 5000 Overlook Avenue, SW Washington, DC Phone: