Crews dig an open trench to lay the new sewer pipe, after which the trench is backfilled and the landscaping/surfacing is restored.

Crews dig entry and exit pits for a drilling machine to bore underground and install new pipe. This method causes minimal disturbance to the surface and can be used in narrow spaces where open trenching would be very difficult or impossible.

We have begun designing the new land-based sewer system and grinder pumps. The project is still in the preliminary design phase and working towards the 30% design milestone. At 30% design, the design concept will be further evaluated before being further refined in engineering detail and used to generate a more accurate cost estimate. Project impacts are still being determined on a property-by-property basis and have not been finalized. The project team held its first round of property owner meetings in November 2021 to collect feedback on the preliminary site plans, including siting of grinding pump stations and associated equipment. It’s important for the project team to hear feedback from property owners early in the design process so their input can be considered and incorporated before design decisions have been made. If you haven’t met with the project team yet, the second round of property owner meetings is anticipated be held in late January 2022 and early February 2022.

The project team will continue to actively evaluate feedback from property owners and incorporate that feedback into individual draft site plans as feasible. We will continue to report on issues and questions raised by Lakeline neighbors in addition to responding to individual concerns and requests. The project team wants to meet with all property owners before reaching the 30% design milestone. If you haven’t met with the project team yet, the second round of property owner meetings is anticipated to be held in late January 2022 or early February 2022. You will be able to sign-up for a property owner meeting by visiting https://kennydalelakeline.participate.online/.

You can also email us at kennydalelakeline@enviroissues.com to request a meeting. We will respond to your meeting request as soon as possible and will stay in touch with you to confirm the meeting date and time. If you prefer an online meeting instead, that can be arranged as well.

We will continue to provide timely information and updates via email, our project website, and other outreach as the project progresses. This is a very important project to ensure the long-term viability and operability of the sewer system that services your home, and we want homeowners to be active partners in this project. If you have questions, would like to request an interpreter for the meeting, or need additional information before scheduling a property owner meeting, please contact the city’s project manager John Hobson, at jhobson@rentonwa.gov.

The existing Lakeline was constructed in 1971 and was constructed of 8-inch cement-lined cast iron pipe. Beginning in 2016 and continuing through 2018, the city and its consultants conducted the Kennydale Lakeline Assessment Project to evaluate the existing condition of the in-lake sewer system. Results from the assessment determined that the aging pipes (50+ years old) were nearing the end of their service life and required replacement.

The city conducted a cleaning project in 2018 to address the immediate needs of the system by cleaning the inlake sewer main and removing partial blockages. Due to the many bends in the sewer, the city was unable to clean and inspect approximately 20 percent of the Lakeline. Therefore, the conditions that caused these blockages remain, and the condition of those sections of pipe remain unknown. The in-lake pipes appear to be degrading both from the inside and outside due to a combination of age and interaction of pipe material and the environment they are around. Because of the inability to readily access the Lakeline, a full blockage or failure of the Lakeline sewer system would result in interruption of all sewer service to Kennydale Lakefront homes until the emergency could be resolved. Because there would be no way to determine where the blockage was in the sewer, and the need to arrange for the necessary barges, divers, and specialty equipment to locate the blockage and make repairs, the existing system could be out of operation for several weeks or months. Should the sewer main corrode through or break, raw sewage could flow into Lake Washington causing an environmental emergency. The goal of the project is to address the deteriorating condition of the pipes and ensure construction of a new fully accessible sewer system before an incident occurs which can shut down the existing sewer system.

The city evaluated numerous construction alternatives before selecting the land-based system. The alternatives considered included: replacing the Lakeline in its current location; moving the in-water sewer line further offshore; and multiple options for land-based sewer systems. To learn more about the alternatives that were evaluated visit the project website.

Current state and federal environmental permitting regulations require that an on-land option is pursued over in-lake options, if technically feasible. Grinder pumps are the only feasible land-based option and have far lower estimated costs ($7-ic million) than the in-lake alternatives ($25 million for in-place and $52 million for further into the lake). Septic tanks were not considered because King County and state regulations prohibit their use in shoreline areas.

A land-based sewer system can be readily accessed for routine and emergency repairs. There are no environmental permits required to gain access and maintain this type of system.

An in-lake system cannot be readily accessed for routine or emergency repairs. To undertake only repairs or maintenance requires extensive permitting (from the Army Corps of Engineers, Washington State Department of Ecology, Washington State Department of Fish and Wildlife, Native American Tribes, etc.) for any work in or near the lake. Some of these permits have a “fish window” which only allows work to take place between July 1 and September 30. In-lake work requires water-based equipment (barges and underwater manhole access caissons) and specialized personnel which takes time to arrange for and is very costly. In addition, annual maintenance of the Ballard Locks can restrict the ability to mobilize the necessary barges to get them to an in-lake sewer system. Much of the southern portion of the current lake-line is in water that is too shallow to allow a barge to get close enough to perform work on the sewer. The existing private docks extend far enough into the lake, and are in close enough proximity to each other, to prevent a barge from reaching much of an in-place sewer replacement.

When the wastewater reaches a certain level inside the grinder pump tank the pumps will grind the sewage into a slurry and discharge it into a pressurized sewer line connected to a new force mainline in the roadways east of the homes. The pump turns off automatically when wastewater is below the activation threshold.

Each individual pump station will be sized for year-round typical occupancy of a single-family home, regardless of current use or historical use in the past. The current plan is to install the largest pump station allowable based on each property’s site constraints. For most properties, this means a 231-gallon holding tank. A tank of this size will allow for normal usage for up to one day in case of a power outage.

The current proposal is to power the grinder pumps utilizing power from the respective properties' electrical service. This may be through a separate meter or through improvements to the existing service.

The grinder pumps run on electricity and will not function during a power outage. However, the pump tank is designed with extra storage for these situations and can accommodate some water use during power outages. In the rare event of an extended outage duration, property owners may need to limit water usage and/or the City may need to manually empty individual pump stations.

We are aware of concerns for pump station operations when power outages occur. Backup power schemes are currently being evaluated by the project team, with additional backup plans in case of a prolonged power outage. We will also be consulting with King County and Puget Sound Energy to identify ways to reduce power outages.

Grinder pumps are designed with an alarm and warning light to indicate when wastewater in the tank reaches a certain level. This can occur from large amounts of water entering the tank at once or during power outages. Once the pump is able to pump out excess water in the tank, the alarm will turn off. Property owners should contact the city if the alarm and the warning light are activated and do not turn off.

The grinder pump system is different in terms of complexity and cost of construction per customer relative to the typical gravity sewer systems in Renton. The final cost of the project is being refined as design progresses and impacts are known. As of right now, the city intends to pay for the installation of the new sewer system and abandonment of the Lakeline through our Sewer capital improvement program. The cost of ongoing maintenance will be evaluated with completion of design. We are evaluating the best way to recover these additional costs with an understanding of the impact to the individual homeowner as well as other rate payers in the city. This will include conducting a financial analysis to evaluate how the project impacts the city’s monthly residential sewer rates.

The city has heard concerns about the significant change to the existing sewer system. Maintenance options and monitoring systems are still being developed by the design team, which is typical in the early design process. Based on early feedback from homeowners, the design will include remote monitoring of the new land-based sewer system by the city, with additional monitoring support provided by homeowners (via on site alarm) as a backup to the remote monitoring. Once the project is fully designed, the city will have a better idea of the city’s responsibilities and the homeowner’s responsibilities. The city will provide that information to the homeowner as the design progresses and in advance of construction.

Construction is currently anticipated in 2024.

During construction residents can expect:

• Construction equipment on or near the road.
• Construction crews directing traffic as necessary.
• Road and individual property access will be maintained to the maximum extent feasible but some delays may occur. This will be coordinated with property owners and residents.
• Some dust, noise, and vibrations typical of construction work.
• Use of heavy equipment on each property and in the roadway.