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