Companies listed here are Trust members and/or program supporters. [A one year listing is complementary for members contributing at the $250 or above level. All revenue from the Company web site listings is used to support the education programs of the American Ground Water Trust. For information about how your company can be included send an e-mail to email@example.com
[While the Trust believes that the company web sites contain useful information about ground water, wells and the ground water industry, the listing of a company does not indicate that the Trust specifically endorses any particular product or service, nor that the Trust takes any responsibility for the accuracy of information or advice that may be offered by the listed sites.]
Additionally, the Trust provides complimentary web-links for non-profit organizations, government & state agencies, universities and professional associations. To view these links go to www.agwt.org/edu_links.htm.
BFA, Orlando, FL
BFA, established in 1994, is an environmental engineering and hydrogeological consulting firm located in Orlando, Florida with satellite offices in West Palm Beach, Miami, and New Orleans, Louisiana. BFA is an SBA 8 (a) certified Minority Business Enterprise (MBE) that provides environmental services to our clients utilizing state of the art technologies.
CH2M, Offices Worldwide
CH2M people help our clients imagine, design and build a better world. We create and operate facilities, infrastructure and systems that bring clean water, safe transportation, efficient industry and life-enhancing technologies and products to people everywhere.
Daniel B. Stephens & Associates , Inc. (DBS&A), Albuquerque, NM
DBSA is a groundwater hydrology and engineering consulting firm with particular expertise in quantitative watershed and hydrogeologic investigations; water resource planning and development; groundwater recharge; conjunctive use; sustainable groundwater management; numerical modeling; water rights; studies of contaminant transport in soil and groundwater; remediation of soil and groundwater; custom solutions for data management and mapping; and expert technical support for environmental and water resource disputes. As a Geo-Logic Associates, Inc. (GLA) affiliate, DBS&A has 250 professionals and 27 offices in the U.S. and abroad.
GEOSCIENCE Support Services, Inc., La Verne, CA
GEOSCIENCE provides integrated, expert groundwater consulting services specializing in groundwater supply, develoopment and management. Since 1978, GEOSCIENCE has partnered with major water districts, municipalities, engineering firms, and government agencies to create practical, customized ans scientifcally sound solutions to their most complex groundwater challenges.
GHS, LLC, St Petersburg, FL
GHS, LLC, is a team of highly-trained, licensed, and motivated environmental professionals. Our staff experience combines a variety of disciplines that specialize in water resource and environmental consulting. The diversity of our experts includes water resource & supply planning, hydrology, land development, permitting, water quality studies & monitoring, wastewater & storm water treatment, and general ecological support.
Golder Associates Inc., Redmond, WA
GOLDER ASSOCIATES is a global group of consulting companies, specializing in ground engineering and environmental services. Golder has 4,000 employees and offices in Africa, Asia, Australia, Europe, North America and South America.
Ground Water Solutions, Inc., Houston, TX
GROUND WATER SOLUTIONS provides hydrogeological consulting services to private industry with emphasis on environmental and water supply studies.
Hazen and Sawyer
Since 1951, HAZEN AND SAWYER has focused on two critical activities – helping our clients provide safe drinking water to their customers, and controlling water pollution and its effects on the environment.
HYDRO RESOURCES operates within geographic regions: Pacific, Rocky Mountain and Mid Continent. Each one of these regions has divisions comprising: hydrological service, design and construction of well and pump systems, well and pump system maintenance, and monitoring programs that insure continuous operation.
MWH Americas, Cape Coral, FL
MWH is an international full-suite engineering services company involved with water-quality improvement, environmental restoration, productive water reuse, and strategic environmental resource planning. MWH provides services relating to watershed management, river basins, streams and reservoir enhancement and rehabilitation, watershed hydrology, water rights and irrigation.
Schlumberger Water Services, Houston, TX
SCHLUMBERGER WATER SCIENCES has expertise in all aspects of conventional groundwater and alternative water supply development including managed aquifer recharge, and water supply development and concentrate disposal for desalination systems. SWS is committed to understanding and developing sustainable subsurface water solutions.
Stetson Engineers Inc., San Rafael and West Covina, CA and Mesa, AR
Established in 1957, STETSON ENGINEERS is a water resources consulting firm providing ground-water evaluation and development, surface water hydrology, environmental engineering, water rights and expert witness services.
Well Water Connection
WELL WATER CONNECTION is a full-service Water Well Design and Project Management company providing consumers with a unique approach to custom-designed irrigation wells and pump related services.
Laval Underground Surveys, Fresno, CA
LAVAL UNDERGROUND SURVEYS water well and borehole video inspection systems pinpoint problems, identify and record actual downhole conditions, promote service work and save time and money. Video inspection is a professional tool for the ground water, environmental monitoring, oil, gas and mining industries.
Baroid Industrial Drilling Products, Houston, TX
BAROID IDP supplies a comprehensive line of drilling fluid products, bentonite grouts, well development and well remediation products to the industrial drilling industry. Backed by a world-wide distribution network, Baroid IDP services the industry by providing customer training workshops, ongoing R & D, well site expertise and optimal performance of products.
CETCO, Hoffman Estates, IL
CETCO offers a wide array of products ranging from drilling fluids, grouts, sealants, polymers, additives, slurry solidification products to well rehabilitation products. CETCO is a leader in product diversity, the CETCO team of field engineers and research scientists offer drillers advanced technical support and continuous product development.
McCrometer, Hemet, CA
MCCROMETER is committed to developing innovative, high-quality, precision flow meters for the most demanding liquid, steam and gas flow measurement for our worldwide customers. Because flow matters, for all of us.
Pumpsight, Fresno, CA
PUMPSIGHT provides complete pump and irrigation system monitoring solutions. Pumpsight solutions are simple to configure, but provide powerful and actionable information for flow, efficiency, cost, and hardware failures.
Bosch Thermotechnology, Londonderry, NH
BOSCH THERMOTECHNOLOGY is a leading source of high quality water heating and comfort heating systems. The Company offers Bosch tankless, point-of-use and heat pump electric water heaters, Bosch solar thermal systems, Buderus floor-standing and wall-hung boilers, Bosch geothermal systems as well as controls and accessories for every product line.
ClimateMaster, Oklahoma City, OK
CLIMATEMASTER is an industry leader in advancing the form, fit and function of Water-Source and geothermal heat pumps. ClimateMaster's 387,000 square foot production facility produces over 50,000 units per year. It has one of the largest testing facilities of any Water-Source Heat Pump manufacturer and works closely with the International Standards Organization (ISO), the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE), the Canadian Standards Association (CSA-US), the Electrical Testing Laboratories (ETL), and Conformit' Europ'ene (CE) to insure that its equipment meets the highest industry standards.
REHAU, Inc., Greensboro, SC
REHAU North America is a leading supplier of polymer-based solutions that reduce energy costs, create healthy, safe environments and conserve finite resources, with products used in many industries including ground source heating & cooling.
WaterFurnace Renewable Energy, Inc., Fort Wayne, IN
WATER FURNACE International. is a premier manufacturer of geothermal heating, air conditioning and air purification systems.
Eastern Analytical, Inc., Concord, NH
EASTERN ANALYTICAL, INC. is an employee owned certified environmental laboratory serving New England. Services also include Direct Push Sampling (soil/groundwater/vapor/mini-well instillation) & Equipment Rental. Providing quality data, reliable turn around time and competitive pricing since 1981. Electronic Data Deliverables & courier service available.
Weck Laboratories, Inc., City of Industry, CA
WECK LABORATORIES, INC. is full service analytical laboratory, certified for environmental, consumer products and food testing, with more than 50 years of experience, dedicated to high quality analytical service that addresses testing needs over dozens of industries across the United States.
Best Best & Krieger, CA and Washington, DC
Established in 1891, BEST BEST & KRIEGER LLP is a full-service law firm with nearly 200 attorneys in nine offices across California and in Washington, D.C. With nearly 100 years of water law experience, BB&K attorneys are national leaders in advising and resolving water-related issues. We deliver effective, timely and service-oriented solutions to complex legal issues facing public agencies, businesses and individuals.
Brownstein Hyatt Faber Schreck, LLP, Santa Barbara, CA & Washington, D.C.
BROWNSTEIN HYATT FABER SCHRECK, has been at the forefront of water law for more than 30 years. With offices across the Western U.S. and Washington, D.C., our attorneys have expertise in real estate, land use, environmental compliance, business transactions, taxation, litigation, government relations, wealth management, intellectual property and gaming.
The Expert Institute, New York NY
The EXPERT INSTITUTE is a legal services research firm that connects Hydrologists and Environmental Engineering professionals with law firms seeking consultation and expert witness services. The Expert Institute has partnered with over 4,000 firms, both globally and in all 50 states including AmLaw 100 leaders, boutique firms, and solo practitioners.
McCormick Kidman & Behrens LLP, Costa Mesa, CA
MCCORMICK, KIDMAN & BEHRENS, LLP is a law firm that represents individuals, business organizations and public agencies throughout the State of California. The company has special expertise and experience in providing Business, Real Estate & Development Advice; Bussiness and Real Property Litigation; Public Agency Advice and Representation; Water Law; Eminent Domain & Inverse Condemnation; Environmental Law and Estate Planning, Trust and Probate.
Gicon Pumps & Equipment, Abernathy, TX
GICON PUMPS & EQUIPMENT, LTD. is a value-added, pump specialty supplier of the highest quality pumps and related pump systems components. They provide complete, highly efficient pumping systems and services for Agricultural, Commercial, Environmental, Industrial, Municipal, Residential, Turf Irrigation, and Water Well Drilling markets.
Goulds Pumps/ITT Industries, Seneca Falls, NY
GOULDS PUMPS INC. manufactures a complete line of water pumps for residential, municipal, commercial and light industrial applications.
Featuring innovative and adaptable solutions for specific filtration problems for over 40 years, LAKOS Separators and Filtration Solutions has become a world leader.
Lorentz US Corp., Slaton, TX
Founded in Germany during 1993. LORENTZ has pioneered, innovated and excelled in the engineering and manufacturing of solar powered water pumping.
National Pump Company LLC, Peoria, AZ
NATIONAL PUMP COMPANY offers a full range of vertical turbine and submersible pumps serving commercial, industrial, municipal, mining and irrigation needs with capacities to 12,500 GPM and heads up to 1,440 feet. National Pump Company has offices strategically located throughout the United States staffed by experienced field engineers, ready to help solve problems for all brands of pump.
Amtrol Inc, West Warwick, RI
AMTROL serves the needs of residential, commercial and industrial markets for water storage, treatment, heating, expansion and flow control, and a host of related HVAC products. AMTROL employs 1700 people worldwide.
Flexcon Industries, Randolph, MA
FLEXCON INDUSTRIES was founded in 1987 and is a leading manufacturer of pre-pressurized diaphragm tanks for the professional water well market. Flexcon also produces ("CAD") captive air diaphragm tanks for the hydronic heating and domestic hot water markets.
Chino Basin Watermaster, Rancho, CA
CHINO BASIN WATERMASTER is a consensus-based organization facilitating development and utilization of the Chino Groundwater Basin. The Watermaster consists of various entities pumping water from the Basin including cities, water districts, water companies, agricultural, commercial and other private concerns.
City of Pendleton, Pendleton, OR
Public Works: Responsible for providing engineering, construction, and repair services for water distribution, water treatment, storm water collection, wastewater collection, wastewater treatment, streets, and other City projects. The Department works with other utilities and developers in addressing utility easement issues, traffic lighting, street improvements, subdivision development, local improvement districts, and municipal projects.
Cucamonga Valley Water District, Rancho Cucamonga, CA
CVWD provides safe and reliable water and wastewater services to the City of Rancho Cucamonga, portions of the Cities of Upland, Ontario and Fontana, and some unincorporated areas of San Bernardino County. CVWD serves a population of approximately 170,000 customers within a 47 square mile area, which includes approximately 45,000 water connections and 35,000 sewer connections.
Golden State Water Company, San Dimas, CA
GSWC serving Californians for 80 years, is a subsidiary of American States Water and is a public utility company engaged principally in the purchase, production, distribution and sale of water to over 240,000 customers, or one out of every 30 persons in California. GSWC also distributes electricity to more than 20,500 customers in one community.
Jurupa Community Services District
JCSD is a services district servicing potable and non-potable water along with parks, lighting and landscaping for a population of approximately 60,000 residents.
Nob Hill Water Association, Yakima, WA
NOB HILL WATER ASSOCIATION, a private non-profit association, is a water supply system in the West Yakima area (south central Washington State) that has 8,784 service connections and serves approximately 21,690 people. Founded in 1908, it is the largest water system in the Yakima Valley except the City of Yakima.
Sacramento Groundwater Authority, Citrus Heights, CA
The SACRAMENTO GROUNDWATER AUTHORITY (SGA) is a joint powers authority created to collectively manage the Sacramento region’s North Area Groundwater Basin, which includes all of Sacramento County north of the American River.
Santa Clara Valley Water District, Santa Clara, CA
SANTA CLARA VALLEY WATER DISTRICT is the primary water resources agency for Santa Clara County, California. It acts as the county's water wholesaler, its flood protection agency and is the steward for its streams and creeks, underground aquifers and district-built reservoirs.
Santa Margarita Water District, Mission Viejo, CA
The SANTA MARGARITA WATER DISTRICT is the second-largest water district in Orange County, CA. SMWD serves more than 108,000 people through 48,000 residential and commercial connections and also serves ranches in the area’s rural foothills.
Valencia Water Company, Valencia, CA
VALENCIA WATER COMPANY is an investor-owned water company serving approximately 94,000 people in the Santa Clarita Valley, including Valencia , Stevenson Ranch, and portions of Newhall, Saugus and Castaic. The customer base is approximately 86% residential.
Western Municipal Water District, Riverside, CA
WESTERN MUNICIPAL WATER DISTRICT serves more than 17,000 retail and nine wholesale customers with water from both the Colorado River and the State Water Project. Western provides supplemental water to the cities of Corona, Norco, and Riverside and the water agencies of Elsinore Valley and Rancho California.
National Driller, Bensenville, IL
Monthly news and information publication.
Aqua Service, Inc., Cameron, WI
AQUA SERVICE has been providing residential and commercial water systems in northwest Wisconsin since 1969. Services include: residential water wells, high capacity wells for irrigation and communities, water analysis, full service water system repairs and comprehensive water system inspections.
Capital Well Company, Dunbarton, NH
CAPITAL WELL COMPANY provides a full range of services from well drilling and pump installation to treating mineral impurities. As a family's needs change, Capital Well is ready to recommend options to accommodate those ever-changing needs.
Connecticut Valley Artesian Well Company, East Longmeadow, MA
CONNECTICUT VALLEY ARTESIAN WELL COMPANY, a third generation company, has been serving the water needs of residential, commercial, industrial and agricultural customers for over 60 years. It is a full service company drilling wells, installing pumps, installing filtration equipment and servicing all well related products.
Cushing & Sons, Keene, NH
Our residential water well drilling and water pump installation service area includes most of NH, VT & central MA. Because we are uniquely qualified and equipped to drill specialty commercial wells; industrial wells; exploration wells; waste monitor wells; pilings; large diameter bores; high yield dewater wells; high volume water wells; and hydrogeologic fracture work, our commercial and industrial drilling service area expands to cover CT, RI, western ME, eastern NY and most of MA.
Florida Design Drilling, West Palm Beach, FL
FLORIDA DESIGN DRILLING is a Water Well and General Contractor in Florida. We are a technically innovative company providing services for municipal, industrial, irrigation, and commercial wells.
Frontz Drilling Inc., Wooster, OH
FRONTZ DRILLING INC. is a full service water well and environmental drilling company. This third generation family business dates back to the 1930's. We currently operate 15 different types of drilling rigs and employ a staff of 25 personnel having a combined experience record of over 100 year.
Gosselin Water Wells, Derby, VT
GOSSELIN WATER WELLS is a professionally trained and licensed full service well drilling and pump installation company servicing northern Vermont and New Hampshire.
Greene's Water Wells Inc., Gray, GA
With a sound knowledge of well hydraulics, well design and geologic conditions, GREENE'S WATER WELLS offers high quality drilling and well maintenance services for municipal, agricultural, industrial, residential, and environmental applications.
Haynes Drilling Company
HAYNES DRILLING COMPANY has been providing safe, reliable groundwater for homes and businesses in the New River Valley since 1958.
Kouba Well Drilling, Hillsboro, WI
KOUBA WELL DRILLING is the oldest and the largest drilling business in Southwestern Wisconsin. It is family owned and specializes in water well drilling contracting. Their provide water well drilling and servicing, and geothermal heating, tailored to both residential and agricultural water wells.
LaFramboise Well Drilling, Inc.
Since 1955, LAFRAMBOISE WELL DRILLING, INC. has served the drilling and water needs of builders, developers, engineers, municipal and private water companies, state and federal agencies and homeowners in CT, RI, MA and NY. Our technical services include water well drilling, pump system design and installation, well inspecting and pump testing, well development, water filtration and treatment, and environmental/geo-technical drilling.
Layne Christensen Company, Mission Woods, KS
Operating through locations nationwide, LAYNE CHRISTENSEN COMPANY provides complete services for high-capacity groundwater supply: hydrogeologic studies; well drilling and construction; pump services; water system maintenance and rehabilitation; water quality assessment and water treatment solutions via advanced technologies.
Luisier Drilling, Inc., Oconto Falls, WI
Established in 1936, LUISIER is a full-service (drilling, pump installation & water systems) company serving residences, industry, and irrigation. Luisier drill more that 350 wells annually and guarantee wells for 20 years.
McKinney Artesian Well & Pump Supply Company, Inc., Plaistow, NH
Established in 1923, MCKINNEY is a full-service company: artesian well contractors; pumps, parts and supplies dealers; water filtration and purification equipment retail; water well drilling and service; water well pumps sales and service; and hydrofracturing. McKinney is licensed in New Hampshire and Massachusetts.
Skillings & Sons, Inc., Hollis, NH
Established in 1971, SKILLINGS & SONS is a water well contractor specializing in all types of well drilling, installation and service of water treatment systems and well pump systems. Skillings & Sons utilizes innovative water system and treatment products, provides full customer service and offers emergency water well service 365 days a year.
Smith Pump, Hooksett, NH
SMITH PUMP provides water well drilling (domestic, industrial and municipal), pump installation and service as well as water conditioning systems throughout New England. Other services include pump stations for community water systems, flow tests, hydrofracturing, well video taping and ground water source heat pumps.
Steffl Drilling & Pump, Willmar, MN
STEFFL DRILLING & PUMP is a complete well company providing commercial and residential services. The staff has over 50 years of combined experience in well drilling and pump service. The company specializes in hard rock drilling and cathodic protection.
Tumwater Drilling & Pump, Inc., Leavenworth, WA
TUMWATER DRILLING provides well drilling up to 12" in diameter. Tumwater also installs and services pump systems providing a full line of water treatment equipment. Tumwater's retail store has a complete inventory of PVC pipe and fittings.
Yadkin Well Company, Hamptonville, NC
YADKIN WELL COMPANY, a family-owned business since 1964, provides complete water delivery systems (including a variety of pumps) for residential, agriculture and businesses. Serving North Carolina and Virginia counties.
Capital Well Clean Water Center, Dunbarton, NH
CAPITAL WELL has been in the water treatment business for over 22 years. CWCWC has expertise in all aspects of water treatment including water quality issues involving radon mitigation, arsenic removal and mineral removal (particle and dissolved states).
SolmeteX, Inc., Northborough, MA
SOLMETEX® is dedicated to the development and manufacture of specialized technology for the safe and economic removal of heavy metal contaminants. It provides leading edge, advanced products, systems, and expert support to a wide range of companies, municipalities, and consumers in the US and abroad to improve environmental quality, surpass health and safety standards, reduce waste stream costs, and meet increasingly stringent legislation regulating the use and disposal of heavy metals.
Danfoss Flomatic Corporation, Glens Falls, NY
DANFOSS FLOMATIC VALVES is a diversified manufacturer of valves- specializing in Backflow Preventers, Automatic Control Valves, Check and Foot Valves. Available in a wide range of sizes and materials, these valves are specifically designed for the Municipal, Industrial, Domestic and Irrigation Markets.
Eastern Driller's Manufacturing Company, Inc., Columbia, PA
EDM manufactures down-the-hole hammers for well drilling, ranging from 4" to 12" with enough options to enable contractors to work with almost any compressed air equipment. The bits we make fit our 6" and 8" hammers with many sizes and variations.
Schramm Inc., West Chester, PA
SCHRAMM INC. manufactures an extensive line of top-head drive Rotadrills to meet the needs of drilling contractors worldwide. Seven separate models are available for 4- to 32-inch-diameter boreholes using air rotary, mud rotary, DTH hammer, dual tube, hollow stem auger, or casing hammer drilling, and reverse methods.
2M Company, Inc., Offices across the Rocky Mountains and Pacific Region
2M COMPANY is a wholesale distributor in the Rocky Mountain region of the United States. We sell water well equipment and materials to licensed contractors. Our website features our entire catalog online.
Drillers Service, Inc., Hickory, NC
DSI are wholesalers to the water well industry with 18 branch offices. DSI has an environmental division and also manufactures PVC monitor well risers, screens, fittings, locking well covers and other items needed for a complete well insulation.
Flowserve, Irving, TX
FLOWSERVE supplies pumps, valves, seals automation and services to the power, oil, gas, chemical and other industries. They have more than 14,000 employees in more than 56 countries.
Milby Company, Elkridge, MD
MILBY COMPANY is a wholesale distributor of water systems products, water treatment equipment, wastewater products, drilling supplies, pipe & fittings, geothermal & environmental products, and water heaters. We serve the mid-Atlantic region from our offices and warehouses in Maryland and Virginia, and have been in the water supply equipment distributing business for over 80 years.
Preferred Pump, Fort Worth, TX
PREFERRED PUMP is a distributor of products specializing in domestic water systems in the United States selling water products to water well drillers, pump installers, dealers, and contractors. Preferred has 29 branch offices throughout the US.
Premier Pump & Supply, Inc. Belmont, NH
PREMIER PUMP & SUPPLY, INC. is a professionally staffed wholesale supplier of water,wastewater, and water treatment products serving all of New England and New York.Operation's are centralized in Belmont, NH with support facilities located in Fairfield, ME and Troy, NY. Most notable among our strengths is our strong service orientation.
PumpsOK, Oklahoma City, OK
PUMPSOK is a wholesale distributor for Environmental Remediation Supplies, Industrial and Oilfield Pumping equipment.
Cotey Chemical Corporation, Lubbuck, TX
COTEY CHEMICAL CORPORATION was founded in Lubbock , Texas in 1949 by Mr. Bradford J. Cotey. They provide products that can be safely and easily applied by non-technical personnel for maintenance, development or sterilization of household, industrial and irrigation water wells.
Grundfos, USA Headquarters, Olathe, Kansas
GRUNDFOS is a global leader in advanced pump solutions and a trendsetter in water technology. They contribute to global sustainability by pioneering technologies that improve quality of life for people and care for the planet. It is their mission to successfully develop, produce and sell high-quality pumps and pumping systems world-wide, contributing to a better quality of life and a healthy environment.
Horsham Water & Sewer
HORSHAM WATER & SEWER AUTHORITY is a community water/sewer system serving a population of approximately 23,000 people within the Township of Horsham. The Water Authority was organized in 1954 to provide water service, and the Sewer Authority was organized in 1963 to provide sewer service in the Township.
Hose Solutions, Inc., Scottsdale, AZ
HOSE SOLUTIONS manufactures and supplies flexible tubes and hoses. The company has a range of "Boreline" drop-pipe products for use with submersible well pumps. Flexible drop-pipe simplifies, and drastically shortens pump installation time. Our hoses are woven layflat-type hoses that are high pressure and light weight.
Inflatable Packers International (IPI Packers)
IPI builds and designs packer solutions for water wells, including: MIT test tools, Precision Swage Casing and Screen Patch system, pump isolation, aquifer testing and hydro-fracturing. We specialize in large diameter and customer packers.
Merrill Manufacturing Company, Storm Lake, IA
MERRILL MANUFACUTRING COMPANY manufactures and sells more than 4000 items to the well water industry including frost proof yard hydrants, pitless units, kits and adapters, well caps, tank tees and insert fittings.
Johnson Screens, New Brighton, MN
Since 1904 JOHNSON SCREENS® has been a leading manufacturer of industrial filters and water well screens. Johnson's stainless steel filters and screens are used in many different processes because of their strength, precision and design flexibility. Johnson's filtration systems are custom engineered to optimize screening solutions for industries such as refining, petrochemical, mining, water treatment, food and beverage, pulp and paper, surface water and polyurethane casting.
Roscoe Moss Company, Los Angeles, CA
ROSCOE MOSS COMPANY offers a complete selection of casing and screen manufactured from stainless steel, mild steel and PVC, along with other well construction materials.