Amanda Stone Director, Waste Programs Division Arizona Department - PowerPoint PPT Presentation

Amanda Stone Director, Waste Programs Division Arizona Department of Environmental Quality

Emerging Issues in Arizona • Long Term Stewardship • UXOs • Vapor Intrusion • Perchlorate • 1,4-dioxane

Long Term Stewardship: Arizona’s Solution • Declaration of Environmental Use Restriction, enacted in 2000 • Engineering and institutional controls • Groundwater, soil, landfills • Fee and financial assurance • Inspections to verify implementation

Long Term Stewardship, cont. • 66 DEURs filed to date – 61 institutional controls – 5 engineering controls • 1 FTE dedicated to compliance – 128a funding • 97 inspections conducted to date - 1 facility out of compliance

UXOs - Issues • ~ 25 practice bomb target sites DoD FUDs • Urban expansion - encroaching on formerly rural bomb target sites • DoD FUDs prioritization not keeping pace with changing land use patterns • Developers requesting NFA through VRP for residential development – no ADEQ standard for “how clean is clean”

UXOs - Issues, cont. • Williams Field Bomb Target Range # 6 near Florence. • Barriers to sale because of potential liability.

UXOs – Response • Retained consultant to evaluate VRP site work using DoD guidance • Reprioritization requested for several sites • Limit NFA to approval of site assessment/cleanup protocol

Vapor Intrusion - Issues • Emerging issue nation-wide • No enforceable Arizona indoor air standards • Risk communication • Political sensitivity – indoor air samples • Integrity of indoor sampling data

Vapor Intrusion - Response • ADEQ soil rule allows vapor sampling to demonstrate compliance • Working with ADHS to certify lab methods (EPA 8260) • Vapor sampling guidance finalized this year • ADEQ currently evaluating available guidance/models

Perchlorate - Impacts • 480 ppb from Lake Mead contaminated Colorado River • CAP water reinjection into recharge basins and used for irrigation • Concentrations between 4-11ppb in recharged groundwater throughout state • Industrial sites have impacted groundwater

Perchlorate - Response � Lake Mead source (Las Vegas Wash) contained – significant reduction in Colorado River concentrations – under 5ppb � Arizona groundwater health-based guidance level: 14 ppb � Arizona soil standard established: 55 ppm � Soil rule requires residual soil concentrations be protective of groundwater/ecological receptors

Perchlorate - Response • UPCO – RCRA corrective action under consent order and permit • Talley – RCRA (burn ground closure) and APP closure currently being modified. • YMCAS – RCRA permit requires periodic sampling in detonation pit

1,4-Dioxane – Tucson International Airport Area Superfund Site � TCE, PCE, TCA in groundwater – from Air Force Plant 44 operations � 1,4-dioxane used as stabilizing additive for TCA until 1971 � Detection limit was not sensitive enough to detect 1,4-dioxane during original groundwater sampling � ROD finalized to address only VOCs

1,4-dioxane, cont. • Air strippers/pump and treat system installed in 1987 to address TCE, PCE, TCA. Did not remove 1,4-dioxane • Treated water reinjected at plume perimeter, unknowingly spreading 1,4-dioxane • 2002 – large plume of 1,4-dioxane discovered after development of methods with lower detection limit • Reinjection system modified to minimize 1,4- dioxane spread

1,4-dioxane, cont. • No MCL or AWQS • EPA issued administrative order under Safe Drinking Water Act. Order required expedited system installation • EPA cleanup goal for new treatment system at this site – 3ppb • ROD will be modified

1,4-dioxane, cont. • Advanced oxidation treatment system currently being installed (hydrogen peroxide and ozone). • New system operational early 2009