The Winfield S. Mahlie Award is given by WEAT to a person who has made significant contributions to the art and science of wastewater treatment and water pollution control.

Winfield S. Mahlie served as Chief Chemist and Superintendent of Water and Sewage Treatment for the City of Fort Worth from 1921 until his retirement in 1961. During his years in Fort Worth, he served on the first Operators Certification Committee for the State of Texas and was Director of the Texas Water and Sewage Works Short School in 1926 and in 1927. He was elected Chairman of the Sewage Section of the Southwest Water Works Association from 1928-1931, from 1934-1936, and in 1955, and also served as a President of the Texas Water Utilities Association. He was the recipient of the Water Environment Federation Bedell Award for Texas in 1952 and was honored with the prestigious WEF Honorary Membership in 1968. Mr. Mahlie was one of the pioneer originators of Texas Short Schools for Water and Sewerage Works Plant Operators. He helped initiate the licensing program for operators in Texas and had an active role in writing several chapters and editing the Texas Operators Manual. He used family vacation time to travel around the country helping sister cities that requested his help with their water plants. He became known as a "trouble-shooter" chemist for these plants where he would take one sip of water from a plant and correctly advise the operators on the kinds and amounts of chemicals needed to correct their problems. At Texas A&M Short Schools, long lines of wastewater operators from cities throughout Texas would wait to consult him about their local wastewater plant problems. Always ready to answer questions or find out the answers to questions, Mr. Mahlie was affectionately known among his peers as "Mr. Water Treatment". A street at the Fort Worth Village Creek Wastewater Treatment is named in his honor.