Stormwater Management at San Diego International Airport

Transcription

1

2 Stormwater Management at San Diego International Airport 2011 ACI-NA Annual Conference Environmental Affairs Committee Richard Gilb San Diego County Regional Airport Authority October 16, 2011

3 Agenda Brief History of SAN and the San Diego Regional Airport Authority History of Stormwater Management at SAN California Stormwater Permit Regime and Compliance Standards Pollutants of Concern at and in the vicinity of SAN Strategies for Treatment/Control of Pollutants at SAN Overview of SAN Green Build The Terminal Expansion Project Environmental Permits Stormwater Treatment Controls

4 History of SAN and SDCRAA 1927 Charles Lindbergh took off from SD for St. Louis, NY, and Paris New airport location on Pacific Hwy named after Lindbergh Current runway is constructed Port District created and made owner/operator of SAN Terminal 1 constructed Terminal 2 constructed Commuter Terminal opened Terminal 2 Expansion and new roadway system opened SDCRAA takes ownership and operation of SAN from the Port SDCRAA Board adopted the SAN Airport Master Plan Green Build Terminal Development Program begins.

5

6 Federal Stormwater Regulations State Stormwater Regulations MUNICIPAL STORMWATER PERMIT Storm Water Management Program INDUSTRIAL GENERAL STORMWATER PERMIT SWPPP - Municipal Activities - Industrial Activities - Commercial Activities - Residential Activities - Construction Activities - New Development and Redevelopment CONSTRUCTION GENERAL STORMWATER PERMIT SWPPP Facility Operations S A N Facility Projects

7 Industrial General Permit Develop and implement a SWPPP. Inspect facility regularly quarterly, during first storm each month. Collect stormwater samples during the first hour of runoff for the first storm of the season and for at least one other storm during operating hours. Sample for ph, TSS, TOC, SC, toxic chemicals and other pollutants likely to be present in stormwater runoff in significant quantities. Submit a Certified Annual Report to the State. Compliance Standard: Requires Best Conventional Pollutant Control Technology (BCT) and Best Available Technology Economically Achievable (BAT). In short, keeping up with the Jones if your neighbors can afford to do it, you had better be doing it too.

8 Construction General Permit For California, latest version of permit was effective July 1, Develop and implement a SWPPP. The Permit requires a Risk Calculation based on 2 factors: Sediment Risk susceptibility to erosion (time, soil, slope). Receiving Water Risk already has sediment problems. 3 Risk Levels each more onerous than previous. Submit a Certified Annual Report to the State. Compliance Standard: BCT/BAT for ph and turbidity. Water quality standards for other pollutants/chemicals.

9 Construction Permit- Risk Levels Risk Level 1 NO Stormwater sampling, unless BMPs fail or spills not cleaned up (spill clean-up must be documented). Risk Level 2 Subject to Numeric Action Level (NAL) - must sample runoff 3x s daily for every qualifying storm year-round. Risk Level 3 Subject to Numeric Effluent Level (NEL) - must sample runoff and receiving water for every qualifying storm year-round. Qualifying storm determined retroactively, so sample every storm. Permit features post-construction requirements, unless the project is located in the jurisdiction of a NDPES Phase I Muni entity. SAN is very flat and San Diego Bay not impacted for sediment, so projects with less than 2 years of soil disturbance are Risk Level 1. Permit includes USEPA Small Construction Erosivity Waiver: Projects less than 5 acres & with R less than 5, submit NOI & fees, but do not need a SWPPP. For SAN, applies April November.

10 Municipal Stormwater Permit

11 Municipal Stormwater Permit Develop and implement a SWMP (similar to a SWPPP). Inspect Municipal, Industrial, Commercial, and Construction sites and activities regularly. Collect dry weather samples of any discharges or standing water discovered during at least one facility inspection conducted during the months of June, July, August, or September. Submit a Certified Annual Report to the State. Compliance Standard: Effluent Limits (runoff water quality standards) are currently impractical, so an iterative process of BMP development, implementation, and assessment is allowed. BMPs must reduce pollutant discharges to the Maximum Extent Practicable (MEP) - No statutory/regulatory definition.

12 Municipal Stormwater Permit Requirement on the Permittees regarding the oversight of Development and Redevelopment prepare and implement a: SUSMP Standard Urban Stormwater Mitigation Plan. First required by the 2001 Municipal Stormwater Permit: Requires incorporation of BMPs into Project at the Design Phase. Treat either the volume of runoff produced from a 24-hour 85th percentile storm event (0.55 inches at Lindbergh Field) or maximum flow rate of runoff produced from a rainfall intensity of 0.2 inch of rainfall per hour for each hour of a storm event.

13 2007 Municipal Permit. The 2007 Re-issued Municipal Permit, modified the SUSMP Process: Require Low Impact Development (LID) BMPs, where feasible, which maximize infiltration, provide retention, minimize imperviousness, direct runoff into landscaping, and construct impervious surfaces to minimum widths necessary, and Develop and apply criteria so that runoff discharge rates, durations, and velocities from projects are controlled to maintain or reduce downstream erosion conditions and protect stream habitat (hydromodification).

14 Low Impact Development - LID In-line Bioretention Area

15 Total Number of Projects Municipal Stormwater Permit In response to 2001 and 2007 Municipal Permits, the Authority has prepared 4 versions of the SUMSP Jan 2003 initial version in response to 2001 Permit for projects that add 5,000 ft2 of new impervious surface. March 2008 update required by 2007 permit to include LID and remove obsolete / ineffective BMPs. March 2010 updated to require LID for all projects that create, add, or replace 5,000 ft2 of impervious surface. Jan 2011 update to include Hydromodification Plan (HMP) requirements. Not applicable at SAN.

16 LID BMP Selection Authority s Engineering Department, Facilities Management Department, and Environmental Affairs Department are quickly becoming aware of the need to Standardize the LID BMP selection menu: Many manufacturers of similar systems Not compatible / interchange-able Need to standardize to facilitate operation and maintenance of BMPs

17 Stormwater Runoff at SAN acres; 80-90% paved; 14 outfalls; 10 inches of rain per year.

18 Pollutants of Concern at and in the vicinity of SAN Since 1992 Airport activities conducted in compliance with the State Industrial General Stormwater Permit. Since Airport activities have been deemed subject to the San Diego Municipal Stormwater Permit. 19 years of wet weather sampling data and 7 years of dry weather monitoring data. Pollutants of concern: Copper Zinc Bacteria (in a few locations)

19 Wet Weather Stormwater Sampling 10 year history Pollutant of Concern Median Concentration (mg/l) Benchmark (mg/l) No. of Analyses No. of Exceedances Exceedance Frequency (%) Copper (Cu), Total Copper (Cu), Dissolved Zinc (Zn), Total Aluminum (Al), Total Iron (Fe), Total Biological Oxygen Demand (BOD) Chemical Oxygen Demand (COD) Total Suspended Solids (TSS) Oil and Grease (O & G) Specific Conductance (SC) 180 umhos/cm 900 umhos/com Lead (Pb), Total ND Ethylene Glycol ND ph 7.29 ph Units

20 Runway Sources of Copper and Zinc

21 Annual Loads of Copper and Zinc from each Source Area rainy season

22 This is not Lindbergh Field in San Diego

23 Clean Water Act - 303d and TMDLs The Federal Clean Water Act - Section 303d States required to develop a list of water quality limited segments those portions of streams, rivers, lakes, bays, and the ocean that do not meet water quality standards, even after point sources of pollution have installed the minimum required levels of pollution control technology. Every 3 years, States compile and USEPA approves the 303d List. Waters on the 303d List are generally addressed by action plans, called Total Maximum Daily Loads (TMDLs), to improve the water quality. The process to establish a TMDL is complex, cumbersome, and expensive and implementation of the actions required by the TMDL can also be complex, cumbersome, and expensive. The Section 303(d) List for California just approved by USEPA.

24 TMDLs and 303d Listed Portions of SD Bay in the vicinity of SAN

25

26 BMP Recommendations Report In 2006, worked with Mactec Engineering (now AMEC) to identify modifications to existing BMPs and to propose new BMPs to reduce the pollutant loads of copper and zinc. Noted high-efficiency, regenerative air, and vacuum-assisted dry street sweepers would be effective for runway/ramp areas. Recommendations provided for the three land-use categories considered to be the most significant sources, namely: Airport Operations (runways and ramp areas, roofs, and galvanized metal structures); Ground Transportation land uses (parking lots & roadways); Industrial land uses (everything else).

27 Potential Treatment Controls Based on site constraints, treatment controls applicable at SAN: Grassy Swales and Filter Strips; Bioretention; Underground Detention Ponds; Porous Pavement; Underground Sand Filters; and Underground Media Filters. None of the controls were predicted to reduce copper to below benchmark values (inability to treat the dissolved copper fraction), although porous pavement most efficient for parking lots, and bioretention most efficient for runway and taxiway. Austin Sand Filters had highest predicted removal efficiencies, but recommended for drainage basins less than 10 acres with adequate head.

28 Pollutant Load Reduction Objectives Report calculated short-term and long-term airport-wide pollutant load reduction objectives for copper and zinc. The long-term (10-year) pollutant load reduction objectives are: 61 lbs per year for copper (currently 180 lbs from runway alone); 35 lbs per year for zinc (currently 140 lbs from roofs alone). Airport-wide pollutant-load-reduction objectives considered preferable to concentration-based limits at individual outfalls, since such objectives allows the SDCRAA to focus on BMPs for those basins with the highest pollutant loads, as opposed to meeting a concentration-based limit at each outfall. New BMPs are evaluated and prioritized in terms of costs and ability to meet the short- & long-term load reduction objectives.

29 Implementation of Recommendations Report proposed two implementation plans to meet the short-term (5-year) and long-term (10-year) objections. Scenarios implement the same source control BMPs; however, Scenario A recommends treatment controls at the source, and Scenario B proposes treatment controls at the end of the outfall pipes. The SDCRAA is currently implementing Scenario A, but is currently off schedule from the timeline originally proposed. BMP Recommendations Report preceded the adoption of the Airport Master Plan (and foreshadowed permitting issues).

30 Terminal Expansion & RON Apron Project

31

32

33 Permitting and Approvals Regulatory landscape for RON Apron and storm drain outfall: Army Corp of Engineers Permit (outfall only). California Water Quality Control Board, San Diego Region: 401 Certification (for outfall); Construction General Stormwater Permit. CA Coastal Commission Coastal Development Permit. SDCRAA: CEQA (for outfall; NEPA complete with Airport Master Plan); Municipal Stormwater Permit SUSMP Process: Review and approval of Post-Construction Treatment Controls.

34 Specifics: RON Apron & Terminal Expansion Estimated total project cost: $ 800 Million. 38 acres site, including Terminal Roof. Hydraulic head: 5.5 ft No primary POCs the area to which the Apron will drain is not listed for any 303d pollutants and has no TMDLs. Water Quality Volume requiring treatment: 24-hour 85 th percentile storm (0.55 inches) = 1.8 acre-ft = 80,000 ft 3

35 Results of Filter System BMP Evaluation Filter Type Description Cost StormFilter CDS MFS Austin Sand Filter Single vault (24 ft x 48 ft), Needing 2.30-ft of head available, 162 cartridges (15gpm, 18 cartridges). Single vault (24 ft x 48 ft), Needing 2.30-ft of head available, 162 cartridges (15gpm, 18 cartridges), Higher maintenance costs than StormFilter Single vault (75 ft x 225 ft for adequate head), diameter columns, 16 aircraft-rated roof, 18 foundation, 12 walls, Significant maintenance costs. $345,000 $397,000 $1,659,000

36 Results of Infiltration Area BMP Evaluation Type Description Cost Artificial Turf $711,000 Pervious PCC Due to the difficulty of establishing and maintaining vegetation at the airport, vegetated alternatives are not feasible. $711,000 Design: Pervious AC Surface Material Top/Bottom Filter Layers + Geotextile $542,000 Drainable Reservoir Layer PCC Pavers $737,000

37 FAA Evaluated: AC No: 150/ AB; DOT/FAA/AR-06/23 Installed at MCAS Miramar. Artificial Turf

38 BMP Layout Retention/Filtration Area Treating 9.6 arces 0.4 ac-ft WQV Artificial $711,00 Media Filtration System Treating 28 acres 1.4 ac-ft WQV StormFilter Media $345,000

39 But the story doesn t end there Project required a Coastal Development Permit (CDP) from the CA Coastal Commission. CA Coastal Act requires CA Coastal Commission to ensure: the quality of coastal waters, streams, wetlands, estuaries, and lakes shall be maintained through controlling runoff Coastal Commission staff remained unconvinced the BMPs were adequate. Staff has experience from across the state. SDCRAA was seeking 404, 401, and CDP simultaneously. Typically, Coastal Commission would act last and staff would rely on the determinations of the Federal and State agencies. Commission staff asked for further assessment/commitments.

40 Coastal Development Permit CA Coastal Commission staff indicated that one way to ensure that the stormwater system is operating in a manner that protects coastal water quality would be to conduct a monitoring program that assesses the effectiveness of the stormwater system so that modifications (e.g., changes to the filter media or street sweeping program) can be made if needed [and prepare] a plan for adaptive management of the stormwater system to prevent adverse impacts to coastal waters. SDCRAA found the request reasonable and generally already a part of the overall stormwater management program strategy. After several lengthy letters, telephone conferences, and meeting, the final CDP language merely states that the proposed BMPs must be install and monitored for effectiveness as designed.

41 Questions