Site work for a water / sewer project in Ketchikan, Alaska. Conceptual plans call for site work for a water / sewer project.

This 8-inch ductile iron main was installed in 1981. The portion replaced in 2007 failed in a different manner than usually occurs. Unlike electrolytic corrosion that usually creates fairly small pits along the bottom of the pipe where the soils are moist and most conductive; in this case, the entire surface of the pipe was badly pitted. The soil layer around the pipe was black from dissolved iron and smelled slightly of sulfur. There is a possibility that the ductile iron pipe was bedded using rock that contains quite a bit of iron pyrite (fools gold) which is actually iron disulfide. Pyrites reacting with oxygen and water will form Thiobacillus bacteria which generate their energy through oxidizing the iron with a side effect of producing sulfuric acid, which chemically corrodes the iron pipe. Subsequent repairs made in 2017 and 2022 near the Black Bear intersection have shown similar pitting and the ductile iron sewer mains are very likely in the same condition. The entire 720 foot section should be replaced with non-corrodible HDPE plastic pipe. There is no present funding available for its replacement but if there were, it would be a joint venture between Public Works and the Water Division to be designed in 2023 with each of these four utility improvement projects contributing to the combined design contract with a single firm. Should Municipal Assistance Funding ever become available again, this would be a likely project that is already designed and has received ADEC approval for maximum points. It would also require voter approval to enter into loan agreements for the remainder of the funding. If granted, construction could begin in 2027 Project is included City of Ketchikan FY 2023 - 2027 CIP. *Project information has been obtained through a public capital improvement plan (CIP). A CIP is a financial schedule for short- and long-range projects which is updated regularly. Information listed in the CIP often evolves based on funding availability and the project details, including timeline and value, are subject to change. The content management team will continue to pursue additional details as they become available.