Hinkley Groundwater Contamination

It’s not over: it’s just the beginning….Masahiro Yagi

Environmental Economics (ECON 360.01) Prof. Diya Mazumder

Erin Brockovich

• Erin Brockovich (2000), successfully highlighted the issue of environmental conflict by depicting the case of Hinkley Groundwater Contamination.

• http://abcnews.go.com/US/erin-brockovich-fighting-neighbors-toxic-drinking-water/story?id=15120603#.ULxMUYNQVnc

History of Hinkley Groundwater Contamination • Pacific Gas & Electric (PG&E)

operates a compressor station in the town of Hinkley in San Bernardino County, California

• An underground plume of a chemical

called Chromium(VI )

• Lawsuit led by a lawyer Erin Brockovich to represent 600 Hinkley residents against the PG&E

• In 1996, PG&E agreed to pay $333 million to those who claimed health issues due to the contamination, which was the largest settlement in the history of the U.S.

The case has not ended yet!

• The area of chromium(VI) contaminations has expanded in recent years.

• Currently, Hinkley residents have been offered 5 final cleaning up options.

• Regional water board and residents are expected to choose a clean-up option by January 2013.

“What is the best clean-up option for the Hinkley?”

No Project 4B 4C-2 4C-3 4C-4 4C-5Years to 50 ppb Cr6 6 6 6 4 3 20Years to 3.1 ppb Cr6 Not Estimated 40 39 36 29 50Years to 1.2 ppb Cr6 Not Estimated 95 90 85 75 95Maximum Agricultural Units* (acres) 182 446 575 575 1394 575

Maximum groundwater pumping rate (gallons per minute, annual average)

1100 2395 3167 4388 4388 3167

Subsurface (in-situ) treatment? Yes Yes Yes Yes Yes YesAvobe-ground (ex-situ) treatment? Not currently No No Yes, 2 locations

plume core and northern area

No Yes, 1 location near plume core

Key features PG&E continues existing cleanup

without expansion. (Alternative required by

CEQA). Doesn’t address full

extent of plume.

Expands AUs and in-situ zones

over No Project. Groundwater

extraction is not year-round.

Up to 9 AUs, year-round

groundwater extraction using AUs with winter

crops added.

Similar to 4C-2, but year-round

groundwater extraction using 2 aboveground

treatment facilities instead of AUs in winter.

Up to 25 AUs for year-round

groundwater extraction Most

extensive plume capture zone,

fastest cleanup, but most aquifer

drawdown.

Aboveground treatment in plume core

(instead of in-situ). Number of AUs similar to 4C-

2. Removes all forms of

chromium from the high

concentration plume area.

Feasibility Study Estemiated Costs ($million)

N/A 84.9 118 276 173 171

Impact Level (1 is low, 6 is high)Groundwater Drawdown 1 2 4 5 6 3

Aquifer Compaction 1 2 4 5 6 3Plume Bulge 1 2 3 5 6 3

TDS/Uranium byproducts 1 2 3 5 6 3Mn, As, Fe byproducts 1 4 4 3 4 2

Nitrate byproducts 1 2 3 4 4 3Wildlife habitat ot loss 1 2 3 5 6 4

EIR AlternativeElement

Groundwater extraction

contaminated groundwater is pumped from the subsurface (also called the aquifer) to contain the groundwater plume from further migration and is used in one or more of the following ways:

Agricultural treatment(land treatment or agricultural units)

• extracted groundwater is used to irrigate livestock forage crops, such as alfalfa. Cr(VI) in the extracted groundwater is hanged to solid trivalent chromium as it infiltrates through the soil. Cr(VI) is the toxic form of chromium, while Cr(III) has very low toxicity.

Above-ground treatment (ex-situ treatment)

• Where the extracted groundwater is processed through a water treatment plant to remove all forms of chromium (trivalent and hexavalent), which is transported off-site for disposal.

Subsurface treatment (in-situ treatment)

• food-grade carbon substances, such as ethanol, are injected into the groundwater within the aquifer to turn the hexavalent chromium into trivalent chromium which is left in solid form at the water table.

Subsurface freshwater injection

• this method creates barriers of freshwater within the aquifer to deflect the contaminated groundwater towards another direction.

Combinations

Impacts

Water Supply: • Drawdown - aggressive groundwater extraction to contain and clean up plume lowers groundwater levels• Compaction - loss of aquifer water storage capacity due to groundwater drawdown

Impacts (continued)

Water Quality: •Cr plume “bulge” – injection or irrigation causes temporary bulge during remediation•Byproduct formation - increased in-situ treatment increases manganese, arsenic, iron in groundwater

Impacts (continued)

Biological Resources: • Restricted tortoise movement - AUs may limit desert tortoise movement through valley• Loss of wildlife - could be disturbed, killed during construction/operation

Benefit-Cost Analysis• Benefit– Agricultural benefit– Health benefit Cr[6]

• Cost– Engineering Cost– Social Cost• Health (Nitrate, Uranium)

–Worst case scenario

Focus: Health Risk• Health risk of Cr 6 - Lung cancer

- Allergic dermatitis- Oral cavity, and intestine tumors

• Health risk of bi-products by clean-up– Nitrate

– Uranium – Total Dissolved Solids(TDS) Not available– Manganese Not significant– Arsenic Not significant– Iron Not significant

High Blood Pressure, Diabetes, non-Hodgkin’s lymphoma, Birth defects

Bone cancer, Kidney damage

Social Benefit

Social Cost

Social BenefitCancer Risk• Current Cr[VI] in Hinkley: 7.8ppb• Objective: 1.2ppb• 1.2ppb = 2 in 1 million has a cancer risk if

he/she drinks 2 liters of water that contains this level of Cr[VI] for 70 years.

1-2ppb7.8ppb/0.06ppb… 130 in 1 million have cancer risk (when Cr[VI] = 7.8ppb)

1.2ppb = 2 in 1 million have a cancer risk 130 – 2 = 128 people are saved

Social Benefit = costs of cancer treatment x 128

Social Benefit• extracted groundwater is used to irrigate

livestock forage crops, such as alfalfa• Benefit

-profit for the local farming community and using the resource for its current highest productive use

-potentially reducing the import of potable water for agriculture

-job opportunities for local farmers

• Uranium- Increase from 4ppb to app. 80.5ppb (Worst

Case Scenario)

• Nitrate - Increase from 10ppm to 10.5ppm

Social Cost

Bone Cancer + Kidney damage = Social Cost 2.683 in 1 million

= cancer / kidney damage risk

1.5 in 1 million have health risks

High blood pressure + diabetes + non-Hodgkin’s lymphoma = Social Cost

Conclusion

No Project 4B 4C-2 4C-3 4C-4 4C-5

agricultural profit 7,382,437 18,091,026 23,323,633 23,323,633 56,544,598 23,323,633

health benefit (cr6) N/A 2,815 2,864 2,913 3,015 2,815

total benefit 7,382,437 18,093,841 23,326,497 23,326,546 56,547,613 23,326,448

engineering costs N/A 84,900,000 118,000,000 276,000,000 173,000,000 171,000,000

health cost (uranium and nitrogen) 342 410 478 613 680 477

total costs 342 84,900,410 118,000,478 276,000,613 173,000,680 171,000,477

benefit-cost (7,382,095) -66,806,569 -94,673,981 -252,674,067 -116,453,067 -147,674,029

Discussion

• People’s perception toward risk• Influence of media• Politics(Regional water association, PG&E)• Different preference for the clean-up option

Reflection upon research

• Difficulty of monetizing social and environmental cost/benefit

• Uncertainty