History of the TCEQ and Its Predecessor Agencies
Natural resource programs were established in Texas at the turn of the 20th century, motivated initially by concerns over the management of water resources and water rights. In parallel with developments in the rest of the nation, and at the federal level, state natural-resource efforts broadened at mid-century to include the protection of air and water resources, and later to the regulation of generating hazardous and non-hazardous waste.
During the 1990s, the Texas Legislature moved to make natural-resource protection more efficient by consolidating programs. This trend culminated in the creation of the Texas Natural Resource Conservation Commission in the fall of 1993 as a comprehensive environmental protection agency.
Sunset legislation passed by the Texas Legislature in 2001 continued the agency and changed its name to the Texas Commission on Environmental Quality. In 2011, sunset legislation continued the TCEQ through 2023.
The major events in the history of the TCEQ are outlined below. Federal items of importance are in bold.
- The legislature authorizes the creation of the first drainage districts.
- The Irrigation Act creates the Texas Board of Water Engineers to establish procedures for determining surface water rights.
- The Texas Board of Water Engineers publishes its first rules and regulations.
- A constitutional amendment authorizes the creation of conservation and reclamation districts as needed.
- The legislature creates freshwater supply districts.
- The legislature organizes water control and improvement districts.
- The legislature creates the first river authority (the Brazos River Authority).
- Legislation authorizes the Texas Department of Health to enforce drinking water standards for public water supply systems.
- Legislation declares that groundwater is private property.
- The legislature creates underground water–conservation districts.
- The Texas Department of Health conducts the first air study in Texas.
- The legislature creates the Texas Water Pollution Control Advisory Council in the Department of Health as the first state body charged with dealing with pollution-related issues.
- The U.S. Congress passes the Water Pollution Control Act.
- Texas’ first air-quality initiative is established when the state Department of Health begins air sampling.
- The legislature creates the Texas Water Development Board to forecast water-supply needs and fund water-supply and conservation projects.
- Congress passes the Atomic Energy Act.
- The Texas Pollution Control Act establishes the Texas Water Pollution Board, and eliminates the Water Pollution Advisory Council, creating the state’s first true pollution-control agency.
- A water well drillers’ advisory group is established.
- The Injection Well Act is passed, authorizing the Texas Board of Water Engineers to regulate waste disposal (other than that from the oil and gas industry) into the subsurface through injection wells.
- The Texas Board of Water Engineers becomes the Texas Water Commission, with additional responsibilities for water conservation and pollution control.
- The Texas Water Pollution Board adopts its first rules and regulations.
- Congress enacts the Federal Clean Air Act.
- Congress passes the Federal Water Resources Planning Act.
- The Texas Clean Air Act establishes the Texas Air Control Board in the Department of Health to monitor and regulate air pollution in the state.
- The Texas Water Commission becomes the Texas Water Rights Commission and functions not related to water rights are transferred to the Texas Water Development Board.
- The Water Well Drillers Act establishes the Water Well Drillers Board.
- The first Texas Air Control Board members are appointed.
- The Texas Water Quality Act establishes the Texas Water Quality Board, assuming all functions of the Water Pollution Control Board. The TWQB adopts its first rules.
- The Texas Air Control Board adopts its first air-quality regulations.
- Texas takes over most federal air-monitoring responsibilities.
- The Texas Solid Waste Disposal Act authorizes the Texas Water Quality Board to regulate industrial solid waste, and the Texas Department of Health to regulate municipal solid waste.
- A presidential order creates the U.S. Environmental Protection Agency (EPA).
- The federal Clean Air Act is amended, requiring states to develop State Implementation Plans.
- The EPA adopts National Ambient Air Quality Standards (NAAQS).
- The legislature first authorizes municipal utility districts.
- The Texas Air Control Board establishes an air permits program.
- Congress passes the Federal Clean Water Act.
- The Texas Air Control Board submits the first State Implementation Plan to the EPA. It also deploys the first continuous air monitoring station.
- The legislature removes the Texas Air Control Board from the Department of Health, making it an independent state agency.
- Texas et al. vs. the U.S. Environmental Protection Agency challenges the EPA’s plan for controlling ozone in Texas.
- The Texas Air Control Board completes deployment of the first continuous-monitoring network.
- Congress passes the Safe Drinking Water Act.
- Texas Air Control Board proposes Texas’ Five-Point Plan as an amendment to the Federal Clean Air Act.
- Congress passes the Resource Conservation and Recovery Act (RCRA) to govern the disposal of all types of solid and hazardous wastes.
- The Federal Clean Air Act and Clean Water Act are amended.
- The legislature creates the Texas Department of Water Resources by combining the three existing water agencies. A six-member board is set up as a policymaking body for the new agency. The Texas Water Development Board is retained as the legislative and policy-making body. The Water Rights Commission is renamed the Texas Water Commission and sits as a quasi-judicial body that rules on permits. The Water Quality Board is abolished.
- The EPA establishes National Ambient Air Quality Standards for lead.
- The Texas Air Control Board submits revisions of the State Implementation Plan to the EPA.
- Congress passes the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), better known as the Superfund bill, to pay for the cleanup of contaminated sites.
- Congress passes the Federal Low Level Radioactive Waste Act
- The Texas Air Control Board submits a plan for addressing lead pollution to the EPA.
- The legislature creates the Texas Low-Level Radioactive Waste Disposal Authority, with responsibility for siting, operating, and decommissioning a disposal facility for commercial low-level radioactive waste.
- The Texas Air Control Board submits a Harris County ozone plan to the EPA. It also reorganizes its monitoring network and relocates continuous air-monitoring stations.
- Texas receives primary authorization for registration and permitting of underground injection control from the EPA.
- Congress passes the Hazardous and Solid Waste Amendments (HSWA) to the Resource Conservation and Recovery Act.
- Texas receives final RCRA authorization from the EPA.
- Congress passes amendments to the 1980 Federal Low Level Radioactive Waste Act.
- The legislature dissolves the Department of Water Resources and transfers regulatory enforcement to the recreated Texas Water Commission, and planning and finance responsibilities to the recreated Water Development Board.
- The legislature moves the Water Rates and Utilities Services Program from the Public Utility Commission of Texas to the newly created Texas Water Commission.
- The Texas Air Control Board mobile sampling laboratory is first deployed.
- Congress passes the Superfund Amendments and Reauthorization Act, re-authorizes CERCLA, and creates the Toxic Release Inventory.
- Congress amends the Safe Drinking Water Act.
- Congress passes the Water Quality Act of 1987.
- Texas establishes an EPA-approved state wellhead-protection program.
- The legislature expands and funds the Petroleum Storage Tank Program.
- The Texas Radiation Control Act authorizes the Texas Department of Health to license the disposal of radioactive waste.
- Congress adopts the Clean Air Act amendments of 1990.
- Congress passes the Oil Pollution Act.
- The Texas Water Commission receives initial authority for the federal HSWA.
- The Texas Air Control Board is expanded to implement the 1990 Amendments to the federal Clean Air Act.
- The legislature, in special session, creates the Texas Natural Resource Conservation Commission, to be effective Sept. 1, 1993. Preparation begins for the consolidation of the Texas Water Commission and the Texas Air Control Board into the TNRCC.
- The Texas Water Commission acquires responsibility for drinking water, municipal solid waste, and the licensing of radioactive substances from the Texas Department of Health.
- The Water Well Drillers Board and the Board of Irrigators are merged into the the Texas Water Commission.
- The Texas Natural Resource Conservation Commission begins operation, bringing together for the first time regulatory programs for air, water, and waste.
- The legislature adopts HB 1920, which establishes the Tax Relief for Pollution Control Equipment Program to be administered by the TNRCC.
- The EPA establishes the Environmental Performance Partnership Grant (PPG) program, funding states to administer environmental programs such as air pollution control (Section 105 of the Clean Air Act), water pollution control (Section 106 of the Clean Water Act), and nonpoint source management [Sections 205(j)(5) and 319(h) of the Clean Water Act].
- Congress reauthorizes the federal Safe Drinking Water Act.
- The legislature transfers regulation of water well-drillers from the TNRCC to the Texas Department of Licensing and Regulation.
- The legislature returns oversight of uranium mining, processing, and by-product disposal to the Texas Department of Health.
- The TNRCC concludes a Performance Partnership Agreement with the EPA, allowing limited flexibility in federally funded program organization and funding. The aim of the agreement is to allocate resources most appropriately throughout Texas on a regional basis.
- The legislature adopts SB 1, mandating water conservation planning for large water users and requiring development of drought contingency plans by public water suppliers.
- The EPA delegates to Texas the National Pollutant Discharge Elimination System program, becoming the Texas Pollutant Discharge Elimination System administered by the TNRCC.
- The legislature transfers the functions of the Texas Low-Level Radioactive Waste Disposal Authority to the TNRCC.
- The legislature adopts HB 801, which modifies the permitting process for permits administered by the agency for which public notice and opportunity for a hearing are required. The legislation requires early public notice, encourages early public involvement, and requires substantive public comment and agency response. This legislation establishes criteria that would limit the scope of hearings by requiring referral of discrete issues that are in dispute and material to the decision of the commission. This process applies to permits issued by the agency under Chapters 26 and 27 of the Texas Water Code and Chapters 361 and 382 of the Health and Safety Code.
- The agency is continued for 12 years under HB 2912, which changes the TNRCC's name to the Texas Commission on Environmental Quality by Jan. 1, 2004.
- The legislature transfers responsibility for accreditation of environmental laboratories and certification of residential water treatment specialists from the Texas Department of Health to the TNRCC.
- The Texas Environmental Health Institute is created by joint agreement between the TNRCC and the Texas Department of Health to identify health conditions related to living near a federal or state Superfund site.
- The Texas Emissions Reduction Plan (TERP) is established by the legislature to be administered by the TNRCC, the comptroller, the Public Utility Commission of Texas, and the Texas Council on Environmental Technology.
- On September 1, the Texas Natural Resource Conservation Commission formally changes its name and begins doing business as the Texas Commission on Environmental Quality.
The name change was required by our Sunset legislation, House Bill 2912. The Texas Legislature felt that the new name is shorter and gives people a better sense of the agency’s purpose. Plus, it’s more consistent with what other states call their environmental agencies.
The agency name change did not affect any previous permits, registrations, or any other paperwork or transactions between the public and the TNRCC earlier than Sept. 1, 2002. It also did not affect any signs or other postings required of businesses by this agency. All the powers, duties, rights, and obligations of the Texas Natural Resource Conservation Commission are the powers, duties, rights and obligations of the Texas Commission on Environmental Quality. (See the official notice in the Texas Register of March 30, 2002.)
- Under HB 1365, the legislature provides a stable funding source for TERP program activities under the TCEQ and ends funding for TERP-related programs under the comptroller and the Public Utility Commission of Texas.
- The legislature establishes a program for dry cleaning regulation and remediation at the TCEQ with the passage of HB 1366.
- Through HB 1567, the legislature provides for the licensing of a facility for disposing of low-level radioactive waste and establishes procedures for the TCEQ to accept and assess license applications from businesses to dispose of such waste.
- In the third called session, the legislature transfers the technology research and development program within the TERP from the Texas Council on Environmental Technology to the TCEQ.
- The TCEQ implements the Permit Time-Frame Reduction Project, designed to shorten the time it takes to review major uncontested permits.
- The TCEQ initiates the Environmental Monitoring and Response System, designed to improve the agency’s ability to measure environmental conditions in real time, notify the public of potential threats, and respond quickly and proactively.
- The TCEQ undertakes comprehensive review and overhaul of the state’s regulations on municipal solid waste.
- The commissioners direct TCEQ personnel to begin a comprehensive review, including extensive public involvement, of the agency’s enforcement process.
- The legislature authorizes the Clean School Bus Program with passage of HB 3469.
- The TCEQ reviews the extensive public comments on the agency’s enforcement process. The commissioners adopt a number of significant revisions to the process, including a pilot field-citation program, which begins on March 13.
- On March 1, the TCEQ adopts major revision, streamlining, and improvement of state regulations on municipal solid waste.
- The legislature passes SB 1604, which transfers regulatory authority from the Department of State Health Services (formerly the Texas Department of Health) to the TCEQ for commercial radioactive-waste processing, uranium mining, and by-product disposal.
- SB 1604 also addresses the process for TCEQ review of a pending application submitted to the DSHS for a by-product disposal facility proposed for Andrews County.
- In addition, SB 1604 addresses the TCEQ’s underground injection-control program for regulation of in situ uranium mining and requires the TCEQ to administer a new state fee for the disposal of radioactive wastes other than low-level radioactive waste.
- SB 1436 transfers the responsibility for the National Floodplain Insurance Program from the TCEQ to the Texas Water Development Board.
- Passage of SB 12 extends the Texas Emissions Reduction Plan through August 2013. It also expands the uses of TERP funds, including use by the Clean School Bus program.
- SB 12 also amends the Low Income Vehicle Repair Assistance, Retrofit, and Accelerated Vehicle Retirement Program (LIRAP) to enhance its availability and increase grant amounts for the purchase of new vehicles.
- The legislature extends the reimbursement program for leaking underground storage tanks from 2008 to 2012 and requires insurance companies to notify the TCEQ if the owner of a petroleum storage tank has cancelled or failed to renew insurance coverage.
- The legislature passes HB 2714 which requires computer manufacturers to establish recycling programs for computers of their own brand.
- The legislature passes SB 3, HB 3, and HB 4, which amend various sections of the Texas Water Code and set out a new regulatory approach for ensuring surface water to meet the environmental flow needs of river, bay, and estuary systems.
- The legislature grants property owners the right to register and participate in the Dry Cleaner Remediation Fund and imposes additional fees and restrictions on the use of perchloroethylene.
- HB 3732 establishes incentives such as property tax exemptions and expedited permit processing for the use of clean coal, biomass, petroleum coke, solid waste, or new liquid fuel technology in generating electricity.
- The TCEQ adopts the Texas BART (Best Available Retrofit Technology) rule, requiring emission controls for certain industrial facilities emitting air pollutants that contribute to regional haze.
- The Rio Grande watermaster announces the receipt of more than 224,000 acre feet of water from Mexico at the Amistad reservoir near Del Rio, effectively eliminating Mexico’s water debt to the United States.
- On Dec. 18, the governor submits to the EPA his recommendation that all areas of Texas meet the revised the 24-hour standard for fine particulate matter (PM2.5) under the National Ambient Air Quality Standards.
- In early 2008, the TCEQ upgrades its electronic permitting system (ePermits) for submissions of applications for the storm water general permit. After the program upgrade, usage rose from 22 percent to 53 percent.
- The TCEQ responds to the aftermath of Hurricane Ike and participating in a massive recovery effort.
- On March 12, the EPA lowers the 1997 eight-hour ozone NAAQ of 0.08 parts per million to 0.075 ppm.
- On May 20, the EPA proposes to lower the NAAQ standard for lead from the current 1.5 micrograms of lead per cubic meter of ambient air.
- As required by the Federal Clean Air Act, the governor of each state submits to the EPA the list of areas that the state believes are not meeting the federal ozone standard. To assist the governor in providing that list, the commission makes recommendations in December on what areas in Texas did not meet the revised ozone standard.
- In March, the governor submits to the EPA the list of areas in Texas that do not meet the 0.075 ppm eight-hour ozone standard.
- The 81st legislature passes HB 1796, which extends TERP through 2019 and establishes the New Technology Implementation Program within TERP.
- SB 1759 establishes the Texas Clean Fleet Program within TERP.
- SB 361 requires water and sewer service providers to submit emergency preparedness plans to demonstrate their ability to conduct emergency operations.
- HB 3547 gives additional enforcement authority to the TCEQ if an owner or operator of a dry-cleaning facility or drop station does not properly register as required under Texas statutes.
- During the special session, the legislature adopts legislation amending the agency’s sunset date from 2013 to 2011.
- The TCEQ responds to record flooding in the Rio Grande area performing essential duties to help control flooding and minimize damage to communities along the border.
- The agency enacts new performance standards for plumbing fixtures sold in Texas as mandated by HB 2667. The standards will help the state save water by 20 percent or more for each plumbing fixture that is installed.
- The TCEQ makes revisions to the State Implementation Plan for the Houston-Galveston-Brazoria metropolitan area that would reduce the cap on highly reactive volatile organic compound cap by 25 percent and bring the area into attainment with the 1997 Eight Hour Ozone Standard.
- The agency implements rules to regulate volatile organic compound emissions created from offset lithographic printing and letterpress printing.
- The TCEQ adopts EPA amendments to the Clean Air Interstate Rule that modifies control periods and heat inputs used to measure nitrogen oxides under this program.
- The EPA enacts a number of final rules relating to greenhouse-gas (GHG) emissions:
- GHG emission standards for light duty vehicles
- Mandatory reporting of greenhouse gases from large sources and suppliers of GHG
- Regulation of GHG emissions for power plants, refineries, and large industrial plants under the Clean Air Act
- The EPA adopts new one-hour standards for nitrogen dioxide at 100 parts per billion and sulfur dioxide at 75 parts per billion.
- The TCEQ responds to and manages the worst one-year drought that has occurred in Texas since records have been kept.
- In January, the TCEQ Internet domain name changes from <www.tceq.state.tx.us> to www.tceq.texas.gov. Our email changes to @tceq.texas.gov at the same time.
- The 82nd Legislature continues the TCEQ for 12 years, until 2023, under HB 2694. The legislation also makes changes to several program areas, such as focusing the Dam Safety Program on the most hazardous dams in the state, transferring the authority for making groundwater protection recommendations regarding oil and gas activities to the Railroad Commission, and increasing the maximum to $25,000 for almost all penalties and $5,000 for others, such as water-rate penalties.
- HB 451 requires the TCEQ to establish a “Don't Mess With Texas Water” program to prevent illegal dumping that affects Texas surface waters.
- HB 1981 modifies the TCEQ’s current Air Pollutant Watch List process, including changes to the requirements for publishing notices and allowing public comment. In addition, the bill requires a publicly available online database for emission events and legislative notification of releases that substantially endanger human health or the environment.
- SB 20 and SB 385 establish three new grant programs under TERP: the natural gas vehicle rebate program, a program to fund natural gas fueling stations, and an alternative fueling facilities program.
- SB 329 creates a program to recycle television-equipment. It includes shared responsibility among consumers, retailers, manufacturers, and the state government.
- SB 1134 prohibits the TCEQ from promulgating new or amending existing authorizations (permits by rule [PBRs] or standard permits) for the oil and gas industry without performing a regulatory impact analysis and extensive monitoring, and considering geographical limitations.
- SB 1258 allows the TCEQ to issue a PBR to enable counties or municipalities with a population of 10,000 or less to dispose of demolition waste from buildings that are abandoned or found to be a nuisance. Disposal can only occur on land that is owned by the county and would qualify for an arid exemption.
- In preparation for the 2012 hurricane season, the TCEQ assigns emergency response functions to all 16 of its regional offices, allowing the agency to respond to multiple emergencies within the state.
- The agency hosts its 20th annual Environmental Trade Fair. Over 3,000 attend the event, plus 1,100 exhibitors.
- The Fifth Circuit Court of Appeals rules against the EPA’s rejection of the Texas Flexible Permit Program and finds it to be without basis in the Clean Air Act or implementing regulations. The court remands consideration of the program to the EPA.
- The TCEQ enacts eligibility and requirement rules for the Texas Natural Gas Vehicle Grant Program and Alternative Fueling Facilities Program, and announces $2.3 million in grants to create facilities for alternative fuel in the nonattainment areas of Texas.
- The agency conducts eight drought emergency-planning workshops across the state for local government officials, board members, and water-system operators.
- The TCEQ takes over research responsibilities for the Texas On-Site Wastewater Treatment Research Council and adopts rules requiring risers and covers for on-site sewage facilities.
- The agency updates the PBR for oil and gas sites in urban locations and close proximity to the public in the Barnett shale region, and increases the number of local investigators and gas monitors in the area.
- The TCEQ adopts rules for implementation of a “Don’t Mess with Texas Water” program.
- The 83rd Legislature passes SB 567 and HB 1600, which transfer the majority of water and wastewater utility regulation from the TCEQ to the Texas Public Utility Commission.
- HB 252 requires retail public utilities to report to the TCEQ when their available water supply is less than 180 days.
- HB 2615 increases penalty fees for water-rights holders who fail to submit an annual water-usage report to the TCEQ.
- HB 788 directs the agency to promulgate rules that allow it to issue greenhouse-gas air permits.
- SB 1727 moves several existing programs (the Texas Clean Fleet program, Alternative Fueling Facilities program, and Natural Gas Vehicle Grant program) into the TERP program.
- SB 1532 grants the TCEQ authority to allow small scale injection wells within certain portions of the Barton Springs–Edwards Aquifer Conservation District to facilitate research projects in desalination and aquifer storage and recovery.
- Country music star Kevin Fowler donates his talents for the TCEQ radio and TV spots, including writing and performing the campaign’s jingle, “Take Care of Texas,” on Texas radio and TV stations throughout the summer.
- The EPA issues a final rule that creates exemptions for wells that capture and sequester carbon from its hazardous-waste regulations.
- The EPA approves the Texas Flexible Permit Program. The TCEQ received a favorable ruling on the EPA’s rejection of the program from the Fifth Circuit Court of Appeals in 2012.
- Texas ozone levels set new record lows or equal them in the majority of the state. In 15 years, Houston levels have improved 29 percent while Houston’s population increased 34 percent. Dallas–Fort Worth levels have improved 21 percent while the area also registered a 29 percent population increase. Corpus Christi, Tyler-Longview-Marshall, Austin–Round Rock, and Beaumont–Port Arthur have all showed improvements of 20 percent or more.
- As required by the 83rd Legislature:
- The following TCEQ programs move to the Public Utility Commission: retail public utilities; certificates of convenience and necessity; and the sale, transfer, and merger of public water utilities.
- The TCEQ takes over permitting of greenhouse gases from the EPA as required by HB 788.
- The TCEQ adopts provisions to replace the state’s dual inspection and registration sticker system with a single vehicle-registration sticker, and modifies the method used to collect the state’s portion of vehicle emissions-inspection fees as required by HB 2305.
- The TCEQ modifies the prohibition on outdoor burning to allow prescribed burning for preventing wildfire hazards.
- The TCEQ takes the lead role in hiring contractors for the cleanup and decontamination of Ebola-virus sites in Dallas.
- The EPA finalizes its Tier 3 motor-vehicle emission and fuel standards designed to reduce numerous volatile organic compounds including nitrogen oxides and benzene, as well as sulfur.
- TCEQ Commissioner Toby Baker announces the establishment of two Gulf Coast Centers of Excellence as part of the federal Restore Act and penalty money paid for the Deepwater Horizon oil spill.
- The 84th Legislature passes the following legislation:
- HB 942 transferring the Tier II Chemical Reporting Program from the Texas Department of State Health Services to the TCEQ on Sept. 1, 2016.
- HB 2244 requires the TCEQ to adopt regulations for the transportation, storage, and disposal of medical waste in the state.
- HB 1902 directs the TCEQ to adopt standards for the reuse of graywater and alternative on-site water for domestic, commercial, and industrial purposes.
- HB 2031 adopts provisions for the diversion of treated seawater from desalination technologies, and prohibits its discharge back into a bay or estuary without a permit from the TCEQ.
- HB 655 authorizes the TCEQ to adopt standards for all aquifer storage and recovery projects.
- HB 4097 allows the TCEQ to issue permits for water diversion from the Gulf of Mexico for desalination and industrial use and allows the TCEQ to issue discharge permits.
- SB 394 enables the TCEQ to approve supplemental environmental projects for local governments to come into compliance with environmental laws or remediate environmental harm caused by that government.
- TCEQ adopts formal rules for desalination technologies making it easier for public water systems to submit proposals to the agency.
- Grammy winner Rick Trevino joins country-music star Kevin Fowler as the voices of TCEQ’s Take Care of Texas radio and TV announcements.
- Take Care of Texas unveils a specialty license plate available for purchase by Texas motorists. Most proceeds go directly to Take Care of Texas to further promote environmental outreach and education.
- The TCEQ launches an online application for new licenses called eApplication for Licensing (e-App). It allows users to complete the pre-approval process online and covers the majority of licenses granted by the agency.
- The agency marked 25 years of the Mickey Leland Environmental Internship Program.
- The TCEQ's regional environmental lab in Houston moves into a new state of the art facility in Sugar Land with a built-in cold room, video security system, emergency back-up generator, four new acid resistant fume hoods, and two new Miele laboratory-specific dishwashers.
- The Texas Supreme Court strikes down two air pollution ordinances enacted by the City of Houston and ruled that the ordinances overstepped state law and the TCEQ’s enforcement authority.
- The U.S. Congress passes the Frank R. Lautenberg Chemical Safety for the 21st Century Act amending the Toxic Substances Control Act (TSCA). The law gives the EPA broader regulatory authority in evaluating the health risks for new and existing chemicals.