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Peter Hsiao has 39 years of experience as a first-chair trial lawyer.  He was named Environmental Litigation Attorney of the Year in Los Angeles by Best Lawyers in America, and one of 16 lawyers named as a Distinguished Environmental Advocate by the American Bar Association.  He is one of seven lawyers in the U.S. designated as a Global Leader in Environmental Law by Who's Who Legal.  The National Law Journal identifies him as a Trailblazer in Energy and Environmental Law, and he is named by Chambers, Legal 500, Lawdragon and Super Lawyers as one of the nation’s best environmental lawyers.

Mr. Hsiao is head of the West Coast Environmental, Health & Safety Practice, awarded Environmental Law Firm of the Year by Chambers and Partners in 2024.  Drawing upon his chemical engineering background, he is one of the nation’s leading attorneys in environmental, natural resources, climate change and toxic tort law.  He is a Fellow and former Chair of the Board of Regents of the American College of Environmental Lawyers.  He is also former Chair of the State Bar of California's Environmental Law Section and a former member of the ABA's Standing Committee on Environmental Law.  

He served as senior trial lawyer for the U.S. Department of Justice as an Assistant U.S. Attorney in Los Angeles.  He was lead trial counsel for the EPA and other agencies, and received the Department of Justice’s Special Commendation Award, the U.S. Attorney’s Office Special Achievement Award, and the U.S. Fish and Wildlife Service Golden Eagle Award.  He was appointed as a judge pro tem for the Los Angeles Municipal Court and served as a mediator for environmental cases.

Mr. Hsiao is the editor of the California Environmental and Natural Resources Law Handbook.  He is past-president of the Board of Directors for the Los Angeles County Bar Association's Counsel for Justice.   He is a life fellow of the American Bar Foundation, former chair of the State Bar of California Committee on Legal Services to the Poor, and recipient of the Wiley W. Manuel Award for pro bono legal services.

He graduated magna cum laude with a B.S. in chemical engineering from the University of Utah in 1982.  He received the Outstanding Student Award from the American Institute of Chemical Engineers. He received a J.D. from the University of California at Berkeley in 1985, where he won the McBaine Advocacy Award.

Full Bio

Credentials

J.D., University of California, Berkeley, School of Law

B.S. Chemical Engineering, University of Utah

California

Fellow and Past Chair of the Board of Regents of the American College of Environmental Lawyers

Former Chair, ABA Marine Resources Committee

Former Chair, Environmental Law Section of the State Bar of California

Former Chair, State Bar of California Committee on Legal Services to the Poor

Former Member and Newsletter Author, American Institute of Chemical Engineers

Former Member, American Bar Association Standing Committee on Environmental Law

Former Member, American Chemical Society

Former President of Board of Directors, Los Angeles County Bar Association's Counsel for Justice

Former President, Board of Directors of the Los Angeles County Bar Association Counsel for Justice

Life Fellow, American Bar Foundation

Member, ABA Section on Environment, Energy and Resources

Member, Environmental Law Section, Los Angeles County Bar Association

Distinguished Environmental Advocate


American Bar Association

Los Angeles Environmental Litigation Attorney of the Year


Best Lawyers in America, 2016

Trailblazer in Energy and Environmental Law


National Law Journal, 2015

One of the Nation’s Best Environmental Lawyers


Chambers and Partners, 2013-2024

One of the Best Environmental Lawyers in the United States


Legal 500 and PLC 3000

Leading Cross-Border Environmental Attorney


International Who’s Who of Business Lawyers

One of the Top Environmental Lawyers in Los Angeles


Los Angeles Business Journal

Awarded the U.S. Department of Justice’s Special Commendation Award


U.S. Department of Justice

Awarded the U.S. Attorney’s Office Special Achievement Award


U.S. Attorney's Office for the Central District of California

Awarded the U.S. Fish and Wildlife Service Golden Eagle Award


U.S. Fish & Wildlife Service

Recipient of the Wiley W. Manuel Award for pro bono legal services


State Bar of California

“Peter Hsiao impresses with his ‘extremely broad experience in all types of environmental issue,’ leveraging his experience as a chemical engineer when advising on disputes. His expert trial practice is particularly highlighted, with one client noting: ‘To hear him address a court is pure art.’”


Chambers USA 2015

"A standout for Proposition 65 work. Extremely knowledgeable and practical on how he'll manage the litigation."


Chambers 2024

"He's absolutely amazing, it's a personalized service, his devotion to timeliness and attention to detail is wonderful."


Chambers, 2024

Close

Recognition

Distinguished Environmental Advocate


American Bar Association

Los Angeles Environmental Litigation Attorney of the Year


Best Lawyers in America, 2016

Trailblazer in Energy and Environmental Law


National Law Journal, 2015

One of the Nation’s Best Environmental Lawyers


Chambers and Partners, 2013-2024

One of the Best Environmental Lawyers in the United States


Legal 500 and PLC 3000

Leading Cross-Border Environmental Attorney


International Who’s Who of Business Lawyers

One of the Top Environmental Lawyers in Los Angeles


Los Angeles Business Journal

Awarded the U.S. Department of Justice’s Special Commendation Award


U.S. Department of Justice

Awarded the U.S. Attorney’s Office Special Achievement Award


U.S. Attorney's Office for the Central District of California

Awarded the U.S. Fish and Wildlife Service Golden Eagle Award


U.S. Fish & Wildlife Service

Recipient of the Wiley W. Manuel Award for pro bono legal services


State Bar of California

“Peter Hsiao impresses with his ‘extremely broad experience in all types of environmental issue,’ leveraging his experience as a chemical engineer when advising on disputes. His expert trial practice is particularly highlighted, with one client noting: ‘To hear him address a court is pure art.’”


Chambers USA 2015

"A standout for Proposition 65 work. Extremely knowledgeable and practical on how he'll manage the litigation."


Chambers 2024

"He's absolutely amazing, it's a personalized service, his devotion to timeliness and attention to detail is wonderful."


Chambers, 2024

Matters

Successfully defended Mattel, Inc. before U.S. Supreme Court in case arising from contaminated property dispute in Beaverton, Oregon at site of former View Master facility.

Represented IMC Corporation in defending criminal action regarding alleged illegal take of migratory birds from exposure to process ponds. Negotiated settlement and first-ever wildlife mitigation plan with California Department of Fish and Game under Fish and Game Code Section 3007.

Represented Kano Laboratories in an enforcement action by the California Air Resources Board regarding emissive content and labeling of adhesive coatings. 

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Matters

Successfully defended Mattel, Inc. before U.S. Supreme Court in case arising from contaminated property dispute in Beaverton, Oregon at site of former View Master facility.

Represented IMC Corporation in defending criminal action regarding alleged illegal take of migratory birds from exposure to process ponds. Negotiated settlement and first-ever wildlife mitigation plan with California Department of Fish and Game under Fish and Game Code Section 3007.

Represented Kano Laboratories in an enforcement action by the California Air Resources Board regarding emissive content and labeling of adhesive coatings. 

Represented Mattel, Inc. in relation to volatile organic compound control measures and spray booth issues before South Coast Air Quality Management District.

Served as Port's lead trial counsel in federal court action against citizens group challenging validity of Clean Water Act Section 404 permit and NEPA process for China Shipping Terminal.

Obtained court ordered dismissal of all charges against Thomas Crane Trucking Company in a felony action alleging violations of federal and state law from oil production and servicing operations in the Bolsa Chica area.

Served as lead outside counsel for Shea Homes for stormwater enforcement actions by RWQCB and municipal agencies. Assisted in preparation of SWPPPs and provided counseling and training on wide range of compliance issues and negotiated with citizens' group regarding alleged stormwater releases to Malibu Creek.

Provided legal counsel to the Port of Los Angeles regarding storm water pollution control issues, including advising on the development of new wharf facilities at Pier 100.

Represented Key Energy Services in toxic tort litigation for alleged contamination from TPH and other chemicals in residential neighborhood development in Santa Maria, California. Represented client on appeals to State Water Resources Control Board of orders regarding responsible party status.

Obtained dismissal of criminal charges against Lodi Memorial Hospital related to alleged asbestos removal practices.

Represented the East Bay Regional Park District in a CERCLA case involving a former landfill. Obtained a ruling allocating 95% of the costs to Waste Management, the former owner of the landfill, and only 5% to the Park District, as the site’s current owner.

Served as lead trial counsel in federal court action City and County of San Francisco v. Atlantic Richfield, et al., to clean up historical contamination by numerous tenants at airport. The over $140 million settlement was the largest environmental settlement in California in 2006.

Served as lead trial counsel for the nation's leading diesel engine manufacturers Cummins Engine Company, Inc., John Deere Construction Equipment Company, Detroit Diesel Corp., and Caterpillar, Inc., in the first defense judgment achieved after trial in a Proposition 65 action. 

Served as lead trial counsel to address the nation's largest source of particulate air emissions, the Owens Dry Lake Bed.  Obtained judgment after trial against Department of Water and Power, and settlement in administrative adjudication before California Air Resources Board.  The resulting settlement led to a new State Implementation Plan and shallow flooding of the lake bed. This settlement had a total value in excess of $100 million.

Served as lead counsel for Union Pacific Corporation for the cleanup of the McCormick and Baxter Superfund site due to contamination.  Negotiated a favorable settlement of past cost and future work under a consent decree with U.S. EPA and California Department of Toxic Substances Control.

Served as lead trial counsel for 3M Corporation to defend against Superfund action by the State of California regarding the Cal Compact landfill site in Long Beach, California (State of California v. Atlantic Richfield).  Case resulted in favorable settlement for 3M.

Matters

Successfully defended Mattel, Inc. before U.S. Supreme Court in case arising from contaminated property dispute in Beaverton, Oregon at site of former View Master facility.

Represented IMC Corporation in defending criminal action regarding alleged illegal take of migratory birds from exposure to process ponds. Negotiated settlement and first-ever wildlife mitigation plan with California Department of Fish and Game under Fish and Game Code Section 3007.

Represented Kano Laboratories in an enforcement action by the California Air Resources Board regarding emissive content and labeling of adhesive coatings. 

See more

Close

Matters

Successfully defended Mattel, Inc. before U.S. Supreme Court in case arising from contaminated property dispute in Beaverton, Oregon at site of former View Master facility.

Represented IMC Corporation in defending criminal action regarding alleged illegal take of migratory birds from exposure to process ponds. Negotiated settlement and first-ever wildlife mitigation plan with California Department of Fish and Game under Fish and Game Code Section 3007.

Represented Kano Laboratories in an enforcement action by the California Air Resources Board regarding emissive content and labeling of adhesive coatings. 

Represented Mattel, Inc. in relation to volatile organic compound control measures and spray booth issues before South Coast Air Quality Management District.

Served as Port's lead trial counsel in federal court action against citizens group challenging validity of Clean Water Act Section 404 permit and NEPA process for China Shipping Terminal.

Obtained court ordered dismissal of all charges against Thomas Crane Trucking Company in a felony action alleging violations of federal and state law from oil production and servicing operations in the Bolsa Chica area.

Served as lead outside counsel for Shea Homes for stormwater enforcement actions by RWQCB and municipal agencies. Assisted in preparation of SWPPPs and provided counseling and training on wide range of compliance issues and negotiated with citizens' group regarding alleged stormwater releases to Malibu Creek.

Provided legal counsel to the Port of Los Angeles regarding storm water pollution control issues, including advising on the development of new wharf facilities at Pier 100.

Represented Key Energy Services in toxic tort litigation for alleged contamination from TPH and other chemicals in residential neighborhood development in Santa Maria, California. Represented client on appeals to State Water Resources Control Board of orders regarding responsible party status.

Obtained dismissal of criminal charges against Lodi Memorial Hospital related to alleged asbestos removal practices.

Represented the East Bay Regional Park District in a CERCLA case involving a former landfill. Obtained a ruling allocating 95% of the costs to Waste Management, the former owner of the landfill, and only 5% to the Park District, as the site’s current owner.

Served as lead trial counsel in federal court action City and County of San Francisco v. Atlantic Richfield, et al., to clean up historical contamination by numerous tenants at airport. The over $140 million settlement was the largest environmental settlement in California in 2006.

Served as lead trial counsel for the nation's leading diesel engine manufacturers Cummins Engine Company, Inc., John Deere Construction Equipment Company, Detroit Diesel Corp., and Caterpillar, Inc., in the first defense judgment achieved after trial in a Proposition 65 action. 

Served as lead trial counsel to address the nation's largest source of particulate air emissions, the Owens Dry Lake Bed.  Obtained judgment after trial against Department of Water and Power, and settlement in administrative adjudication before California Air Resources Board.  The resulting settlement led to a new State Implementation Plan and shallow flooding of the lake bed. This settlement had a total value in excess of $100 million.

Served as lead counsel for Union Pacific Corporation for the cleanup of the McCormick and Baxter Superfund site due to contamination.  Negotiated a favorable settlement of past cost and future work under a consent decree with U.S. EPA and California Department of Toxic Substances Control.

Served as lead trial counsel for 3M Corporation to defend against Superfund action by the State of California regarding the Cal Compact landfill site in Long Beach, California (State of California v. Atlantic Richfield).  Case resulted in favorable settlement for 3M.

Credentials

J.D., University of California, Berkeley, School of Law

B.S. Chemical Engineering, University of Utah

California

Fellow and Past Chair of the Board of Regents of the American College of Environmental Lawyers

Former Chair, ABA Marine Resources Committee

Former Chair, Environmental Law Section of the State Bar of California

Former Chair, State Bar of California Committee on Legal Services to the Poor

Former Member and Newsletter Author, American Institute of Chemical Engineers

Former Member, American Bar Association Standing Committee on Environmental Law

Former Member, American Chemical Society

Former President of Board of Directors, Los Angeles County Bar Association's Counsel for Justice

Former President, Board of Directors of the Los Angeles County Bar Association Counsel for Justice

Life Fellow, American Bar Foundation

Member, ABA Section on Environment, Energy and Resources

Member, Environmental Law Section, Los Angeles County Bar Association

Distinguished Environmental Advocate


American Bar Association

Los Angeles Environmental Litigation Attorney of the Year


Best Lawyers in America, 2016

Trailblazer in Energy and Environmental Law


National Law Journal, 2015

One of the Nation’s Best Environmental Lawyers


Chambers and Partners, 2013-2024

One of the Best Environmental Lawyers in the United States


Legal 500 and PLC 3000

Leading Cross-Border Environmental Attorney


International Who’s Who of Business Lawyers

One of the Top Environmental Lawyers in Los Angeles


Los Angeles Business Journal

Awarded the U.S. Department of Justice’s Special Commendation Award


U.S. Department of Justice

Awarded the U.S. Attorney’s Office Special Achievement Award


U.S. Attorney's Office for the Central District of California

Awarded the U.S. Fish and Wildlife Service Golden Eagle Award


U.S. Fish & Wildlife Service

Recipient of the Wiley W. Manuel Award for pro bono legal services


State Bar of California

“Peter Hsiao impresses with his ‘extremely broad experience in all types of environmental issue,’ leveraging his experience as a chemical engineer when advising on disputes. His expert trial practice is particularly highlighted, with one client noting: ‘To hear him address a court is pure art.’”


Chambers USA 2015

"A standout for Proposition 65 work. Extremely knowledgeable and practical on how he'll manage the litigation."


Chambers 2024

"He's absolutely amazing, it's a personalized service, his devotion to timeliness and attention to detail is wonderful."


Chambers, 2024

Close

Recognition

Distinguished Environmental Advocate


American Bar Association

Los Angeles Environmental Litigation Attorney of the Year


Best Lawyers in America, 2016

Trailblazer in Energy and Environmental Law


National Law Journal, 2015

One of the Nation’s Best Environmental Lawyers


Chambers and Partners, 2013-2024

One of the Best Environmental Lawyers in the United States


Legal 500 and PLC 3000

Leading Cross-Border Environmental Attorney


International Who’s Who of Business Lawyers

One of the Top Environmental Lawyers in Los Angeles


Los Angeles Business Journal

Awarded the U.S. Department of Justice’s Special Commendation Award


U.S. Department of Justice

Awarded the U.S. Attorney’s Office Special Achievement Award


U.S. Attorney's Office for the Central District of California

Awarded the U.S. Fish and Wildlife Service Golden Eagle Award


U.S. Fish & Wildlife Service

Recipient of the Wiley W. Manuel Award for pro bono legal services


State Bar of California

“Peter Hsiao impresses with his ‘extremely broad experience in all types of environmental issue,’ leveraging his experience as a chemical engineer when advising on disputes. His expert trial practice is particularly highlighted, with one client noting: ‘To hear him address a court is pure art.’”


Chambers USA 2015

"A standout for Proposition 65 work. Extremely knowledgeable and practical on how he'll manage the litigation."


Chambers 2024

"He's absolutely amazing, it's a personalized service, his devotion to timeliness and attention to detail is wonderful."


Chambers, 2024