The PCE Contamination Problem in California s Central Valley; Recent Developments

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1 The PCE Contamination Problem in California s Central Valley; Recent Developments Antonia (Ton) Vorster, P.E. Groundwater Cleanup Program Manager, Central Valley Region

2 WIDESPREAD PCE CONTAMINATION THROUGHOUT THE VALLEY CHICO OROVILLE ROSEVILLE SACRAMENTO ELK GROVE LODI STOCKTON MODESTO PATTERSON TURLOCK MERCED LOS BANOS FRESNO VISALIA PORTERVILLE BAKERSFIELD CITIES WITH SUPPLY WELLS AFFECTED BY PCE (1992 Survey)

3 Recent California Actions Regional Board Cleanup and Abatement Order to City of Lodi and Other Responsible Parties for Lodi Central Plume Area Numerous Dry Cleaners cooperatively cleaning up under State oversight Merced has volunteered to begin cleanup under State oversight New Brownfield legislation protecting property purchasers performing cleanups

4 INTERESTING LEGAL DEVELOPMENTS Lodi Settlements Central Plume Parties Lehman Insurance Carrier

5 THE LODI CENTRAL PLUME SETTLEMENTS Central Plume Parties have Settled. Creation of City-directed remediation trust $4.5M from Guild Cleaners, $2.2M from Lodi, $2M from Newspaper, $1.5M from Building owners City to assume responsibility for cleanup State to give Covenant not to Sue to settling parties

6 THE LODI SETTLEMENTS (Continued) The City has settled with Lehman; City to Repay Lehman $6.0 Million of $16M Loan The City settled with its insurance carrier; City Received $10 Million for $100K policy

7 THE MODESTO CASE Modesto has won an important ruling from the 9 th Circuit that Manufacturers of Dry Cleaning Equipment could be responsible parties under the California Water Code (119 Cal.App. 4 th 28)

8 Lodi, California

9 Lodi Street Map Northern Plume Busy Bee Plume Central Plume Western Plume Southern Plume

10 Central Plume Dischargers Odd Fellows/RJ and Flair Cleaners Beckman/News Sentinel Alleyway Sewer Line Guild Cleaners

11 Central Plume Dischargers Odd Fellows/RJ and Flair Cleaners Beckman/News Sentinel Alleyway Sewer Line Guild Cleaners

12 Extent of PCE in Soil Gas Guild Soil Gas Samples from 20 feet deep Alleyway Sewer Line 12

13 Extent of PCE in Soil Gas Guild Soil Gas Samples from 30 feet deep 13

14 Extent of PCE in Soil Gas Guild Soil Gas Samples from 40 feet deep 14

15 SVE PILOT TESTING Soil Vapor Extraction/Sparge Testing 7,000 lbs. PCE removed by SVE >600 gallons, >ten 55-gallon drums Air/Ozone Sparge tests also performed

16 TECHNOLOGICAL DEVELOPMENTS FOR INVESTIGATIONS Lodi groundwater investigation by real time CPT and Hydropunch. Lodi pilot study using passive diffusion bag samplers. Indoor air sampling results

17 Lodi Central Plume: CPT & Hydropunch 90 Sand Source Area Downgradient

18 Polyethylene Diffusion Bag Samplers: Lodi Pilot Test Results PDB Samples Low-Flow Historical Sampling Well Depth PCE TCE PCE TCE PCE TCE MW / G-25A < / 190 <2 / < < <2.0 G ,700 < / 300 <2.0 / <2.0 1,400 < ,700 < ,600 < <5.0 MW ,000 / 68,000 <500 / <50 11,000 <63 75,000 <500 / < ,000 <420 6,500 <50

19 Indoor Air Sampling Residences, Schools and Businesses Sampled (21 samples). Outdoor Air Sampled (9 samples). One sample in one business exceeded the One-in-100,000 cancer risk level. One sample in one residence exceeded the one in 100,000 cancer risk level. Summa Canister Indoor and Outdoor Air Sampling Locations

20 California Human Health Screening Levels for PCE in Indoor Air Residential Use: µg/m 3 Commercial Use: µg/m 3 Lodi Residence - 7.8, 2.4 µg/m 3 Fitness Pro - 24, 23 and 9.6 µg/m 3

21 TECHNOLOGICAL DEVELOPMENTS FOR REMEDIATION Stockton pilot study of injecting zerovalent iron with nitrogen carrier A clay zone, beneath the groundwater table, saturated with high levels of PCE SVE/Pump + Treat will take > 30 years Nitrogen, under pressure, would open fractures in the clay allowing penetration of the iron

22 Liquid Nitrogen Pumping Truck

23 Granular Iron Injection Pump

24 Nitrogen/Iron Mixture Injection Tool

25 Nitrogen/Iron Injection Results Technology was effective at deeper groundwater depths, achieving a radius of influence over 20 feet. Nitrogen short-circuited to vadose zone when injected in shallow groundwater Continuing to see PCE reductions in the groundwater over one-year later

26 Nitrogen/Iron Injection Results Well ID Zone Distance to Injection Point Baseline PCE Concentration Eleven-week PCE Concentration Percent Change in Concentration PT-2 Shallow 7 feet 4,400 2,500-47% PT-4 Shallow 12 feet 13,000 11,000-15% PT-1 Deep 12 feet % PT-3 Deep 15 feet 1, % PT-5 Deep 20 feet 3, % PT-7 Deep 23 feet 4,800 2,400-50%

27 For More Information: On CPT testing: On PDB s: On air sampling: (this site also has a nice calculator that converts contaminant concentrations from/to ppbv, µg/l, µg/m 3 ) On California Human Health Screening Levels for Indoor Air and Soil Gas: On Iron Injection:

28 ? QUESTIONS?