2019-04-24 Meeting Minutes (EMC)

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b. Discuss progress and future efforts to identify and control brackish water infiltration in coastal sewer lines. Chair Bennett said it is clear that seawater infiltration into the sewer lines constitutes a real threat to water reuse. The landscape plants will be at risk because of the chloride level. Though he is a proponent of water reuse, he is also sensitive to the fact that you only have one chance to make a first impression. If the water starts killing plants and grass, it will be hard to undo that reputation. He asked Director Kucharski what the plans are to get the infiltration under control. Director Kucharski said there are two areas where infiltration can occur. One is through the sewer lines DEM maintains and controls, and the other is through the laterals from other users. All the force mains along Aliʻi Drive are in the process of being renewed. Continuing to replace the pipes is a 4- to 5-year program, and it disrupts all of downtown as they move along and replace all the gravity and force mains that are subject to tidal influence. In addition, all of the laterals need testing, and there needs to be a specific program developed to do so. There is recent legislation that allows a county to come onto a property to monitor the lateral and require the owner to repair it if significant infiltration is found. However, DEM does not have the manpower and engineering resources at this time to do so. With the recent sewer rate increase, they will be getting more positions created to have more oversight. They could also contract out the work but would need an engineer to write the specs for the contract. The Wastewater Division currently has four engineers, and two of them are junior. The other two are overworked. The long-term plan is to bring in more engineers. He can only say they are working on the Aliʻi Drive project, but their resources are really limited. Chair Bennett asked questions about the chloride levels and said the department appears to be putting bandages on the system to fix the holes. He asked if it was conceivable to install a vacuum system incrementally. Director Kucharski said it is conceivable but would involve not only tearing up the entire Kona street setup but also cost millions of dollars, if not more. Further discussion was held on a vacuum sewer system and whether it could be achieved. Vice Chair Olson said the sea level is rising, and a lot of money could be thrown into a system to which no one could hook up. Chair Bennett said concerns over the rise in sea level are legitimate, and the City and County of Honolulu has a small staff dealing with it. He has reached out to them and is trying to get Josh Stanbro to give a presentation. The cost of incremental inundation will be in the billions of dollars, and the County Council and Mayor’s Office need to get involved. Director Kucharski said the Planning Department in addition to the Research and Development Department are very involved in the issue.