NPDES Permit Public Meeting. Stormwater/Deicing Improvements at GFIA June 13, 2013

Transcription

1 NPDES Permit Public Meeting Stormwater/Deicing Improvements at GFIA June 13, 2013

2 Project Milestones & Requirements Long-Term Alternatives Report September 1, 2011 Approved by DEQ December, 2011 Eliminate GFIA Contribution to Biofilm in unnamed tributary to Thornapple River Completion October 1, 2015

3 Background/Context Why Are We Here? Deicing is required for flight safety Deicing runoff control is necessary and is a challenge Past control practices have been effective, but there is still a seasonal biofilm issue in the unnamed tributary Carriers at GFIA are required to use PG GFIA working with the community and DEQ to fix the issue has identified the best solution

4 Current and New Stormwater Routes

5 Project Summary Consolidate airfield storm flows; relocate outfall along Thornapple River with diffuser; new detention basin; natural treatment systems; sediment and trash control; seasonal by-pass to unnamed tributary.

6 Public Outreach 10 Stakeholder Meetings with all info on GFIA Web Site-(WMEAC, airlines, tenants, Drain Comm., Cascade & Ada Twp., DEQ, Thornapple River Watershed Council, Grand Valley Metro Council, business community, Cascade/Thornapple River Assoc., Thornapple River Assoc., DEQ) Public presentations Cascade Twp., Ada Twp., Caledonia Twp., County Comm., Airport Board Grand Rapids Press Editorial 2 Cascade Twp. Newsletter Articles 2 GFIA Newsletter Articles June 13, 2013 DEQ public meeting on permit June 17, 2013 FAA public hearing on E.A.

7 True or False? Fugitive fraction of deicers will reach the Thornapple and Grand Rivers and cause environmental problems. FALSE

8 Fugitive losses reduce the amount of deicers exposed to stormwater Loss Factor Percent of Applied Deicers Lost Dispersion Into the Air 0 10% 1 Adhesion to the Aircraft 5 15% 1 Jet Blast 5 10% 1 Biodegradation on pavement surface 20 30% 2 1. J. Kieler and J. Stuber. What Happens after When the Plane Takes Off. ACC/AAAE Airport Planning, Design and Construction Symposium Revitt & Worrall, Low temperature biodegradation of airport de-icing fluids. Water Science and Technology Vol 48 No 9 pp

9 Fugitive loss to on-site biodegradation of deicers is a documented fact Apron surface biodegradation rates for deicing products were measured and reductions in the potential BOD load of a typical mixture of deicers over a 5 day period were estimated at 32.9% to 21.4%, depending on temperature. 1 In aerobic soils, propylene glycol degrades to carbon dioxide in 4 days 2 Any remaining BOD or PG in the airport s apron area will enter the natural treatment system for further treatment. 1. Revitt and Worrall. Low temperature biodegradation of airport de-icing fluids. Water Science and Technology Vol 48 No 9 pp US EPA, Registration Eligibility Decision for Propylene Glycol and Dipropylene Glycol, EPA-739-R

10 True or False? Central deicing pads should be installed at GFIA as a better option FALSE 80% of airports use central deicing pads FALSE

11 Central Deicing Pads were analyzed during the alternatives evaluation Several pad configurations were analyzed through conceptual design. At a cost of $23M, pads at GFIA would not reduce organic loading sufficiently to eliminate GFIA s contribution to nuisance biofilms in the unnamed tributary. Pads would negatively impact airfield operations and flight schedules at GFIA.

12 Central Deicing Pads are one tool in the toolbox, and not a silver bullet Centralized deicing may be impractical for all but the largest airport operations due to cost and size industry survey 2 of 183 airports found: 19% reported using deicing pads 32% collect at gates 23% reported using glycol collection vehicles Some use all three 1. Water technology fact sheet airplane deicing fluid recovery systems. EPA ACI-NA/A4A Unpublished industry survey.

13 True or False? The Grand Rapids Wastewater Treatment Plant analyzed the runoff and refused to accept it. FALSE

14 Wastewater Treatment Plant Pilot Discharge Project GFIA sent over 170,000 gallons of runoff to the WWTP during the season during a pilot test project. The POTW lacked available hydraulic and BOD capacity to consistently meet the airport s long-term program requirements. GFIA continues to send high concentration deicing runoff to have the PG recovered and reused.

15 What is Propylene Glycol? Generally Recognized as Safe by FDA 1 and widely used in food, and pharmaceutical and personal care products. Does not present human health effect hazards 1 Acute oral toxicity is very low, and large quantities are required to cause perceptible health damage in humans Serious toxicity generally requires extremely high intake over a relatively short period of time. Prolonged contact with PG is essentially non-irritating to the skin. Does not cause sensitization and it shows no evidence of being a carcinogen or of being genotoxic (damaging to DNA). 1. U.S. Food and Drug Administration Select Committee on GRAS Substances (SCOGS) Opinion: Propylene Glycol.

16 Deicers used at GFIA are in EPA s Safest Category USEPA Ecotoxicity Categories for Aquatic Organisms * Acute Concentration of Product (mg/l) Toxicity Category <0.1 very highly toxic highly toxic >1-10 moderately toxic > slightly toxic >100 practically nontoxic Ecotoxicity of Aircraft Deicers used at GFIA All products, most sensitive species: ,600 mg/l Lowest GFIA product value is 2X safer than EPA s best category Weighted average, most sensitive species: 11,000 mg/l * From: USEPA website, Technical Overview of Ecological Risk Assessment, Analysis Phase: Ecological Effects Characterization,

17 No evidence PG transports pesticides or metals at GFIA or any other airport USGS deicing researchers (S. Corsi, et al.) have seen no evidence of carrier phenomena in their studies. In development of the national deicing regulations, EPA focused on regulating those pollutants exerting oxygen demand {glycols} and contributing toxicity {urea} to receiving water bodies. 1 DEQ testing of GFIA deicing runoff showed no significant priority pollutants 2 or aquatic toxicity US EPA. Technical Development Document for the Final Effluent Limitations Guidelines and New Source Performance Standards for the Airport Deicing Category MDEQ Interoffice memo, Gerald R Ford Intl Airport-GR - Permit Review Recommendations for Toxics National Pollutant Discharge Elimination System (NPDES) Permit No. MI February 9, 2012 and March 2012 MDEQ Permits Section recommendation following review of effluent characterization sample results. 3. MDEQ Interoffice Communication MI/DEQ/WB , Unnamed Tributary of the Thornapple River Downstream of Gerald Ford International Airport Wastewater Input Aquatic Toxicity Evaluation, March 30, 2007.

18 Propylene Glycol Biodegrades Quickly in the Environment Can break down very quickly in surface water and in soil. 1 The presence of PG in the environment, including the atmosphere, does not pose a concern. 2 Known to exert high levels of biochemical oxygen demand during degradation in surface waters. 3 Functions as a food source for biofilms under certain conditions (e.g. the unnamed tributary) 1. Agency for Toxic Substances and Disease Registry, Registration Eligibility Decision for Propylene Glycol and Dipropylene Glycol, US EPA, EPA-739-R Environmental Impact and Benefit Assessment for Proposed Effluent Limitation Guidelines and Standards for the Airport Deicing Category, US EPA, July

19 True or False? The natural treatment system will discharge 7% of the propylene glycol applied at GFIA into the Thornapple River FALSE

20 The treated NTS discharge will contain about 7% of the BOD load from deicing Very little, if any measurable PG will make it through the treatment system under normal operating conditions. The BOD in the treated discharge will be from remnants of the biodegraded deicers. Median BOD levels will be about 32 parts per million, well below GFIA s Clean Water Act permit and will have no impact on the Thornapple River.

21 What is Biochemical Oxygen Demand (BOD)? A measure of the oxygen used by microorganisms to decompose waste. The more organic waste present, the more bacteria there are decomposing this waste and using oxygen, so the BOD level will be high. VT Department of Environmental Conservation There is no relationship at all between BOD and bacterial contamination, toxicity, or other impacts associated with sewerage. BOD can reduce the dissolved oxygen in receiving streams.

22 BOD Content of Sewage and Common Beverages BOD-5 Substance (mg/l) Raw Sewage Whole milk 2 104,600 Coca Cola 3 67,400 Pepsi 3 79,500 Ginger Ale 3 64, USEPA, 2012, EPA-821-R Carawan, R. E., NC State University, Water and Wastewater Management in Food Processing, Sotoike, R., Water and Wastewater Handbook, Maruzen, 1992

23 Natural Treatment Vertical Downflow Design 2 Sets of 6 in Parallel; Avg. area = 15,511 s.f.; Total = 4.27 acres Natural occurring bacteria use glycol as a food source

24 Fraction of Applied Aircraft Deicers GFIA Aircraft Deicers Potentially in Stormwater during Average Winter Events 70% 60% 50% 40% 30% 20% 10% 0% * While early stormwater permits contained *While very limited early mandates stormwater to manage permits deicing contained stormwater very discharges, limited field mandates surveys to manage showed no deicing dissolved stormwater oxygen impact discharges, in the field Thornapple surveys River. showed no dissolved oxygen impact in the Thornapple River. Pre-2000* on

25 Average Seasonal Deicing Material Destination Post Project Completion (2015 +) Fugitive Losses = 36% Collect & Recycle = 28% Treatment Removal = 29% Stormwater Discharge = 7% The 7% potentially available to stormwater represents very dilute BOD from deicer remnants that might not be removed by treatment 32 parts per million median BOD concentration On par with WWTP discharges

26 Thank-You Gerald R. Ford International Airport Board and staff are committed to: Flight safety for passengers Environmental stewardship Cost effective compliance Positive relationships with our neighbors