Deposits discharged through the cleaning mainly were cement mortar, bitumen paintings and rust pieces, and fragments of perforation, stones and gravels. Deposits were more removed through swabbing pig cleaning rather than air scouring cleaning on the whole. However, air scouring cleaning were not influenced by the constraint conditions such as a change in the diameter or the presence of the valve in water mains compare to swabbing pig cleaning. So, it was thought that air scouring cleaning might be more favorable to water distribution network cleaning in the future. After the cleaning, water quality including residual chlorine and turbidity also was improved because of the removal of a significant amount of the deposits. Therefore, if the cleaning is continuously and regularly implemented in water mains, it is expected that it will help to recover the reliability and to preserve the health of water quality.

• 배철호(한국수자원공사 K-water연구원 상하수도연구소) | Cheolho Bae
• 이두진(한국수자원공사 K-water연구원 상하수도연구소) | Doojin Lee
• 최두용(한국수자원공사 K-water연구원 상하수도연구소) | Doo-Yong Choi
• 전홍진(한국수자원공사 K-water연구원 상하수도연구소) | Hongjin Jun
• 박세현(한국수자원공사 K-water연구원 상하수도연구소) | Sehyun Park
• 최태호(한국수자원공사 K-water연구원 상하수도연구소) | Taeho Choi Corresponding author