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Upper NW Interceptor Sections 1 & 2
Fall Update - Project is on schedule!
The Upper Northwest Interceptor 1 & 2 (UNWI 1 & 2) project is a tunnel project to install 3.6 miles of 144-inch diameter sewer pipeline along the East Drainage Canal from the New Natomas Pump Station to Bridgecross Drive. At Bridgecross Drive, UNWI 1 & 2 will connect to the previously constructed Upper Northwest Interceptor Sections 3 & 4.
In order to reduce impacts to the surrounding community, tunneling was chosen as the construction method. The only visible construction activities along the project alignment have been at the manhole construction areas and at the receiving shaft located south of Bridgecross Drive. The manholes were built as the underground tunneling reached the sites and are spaced at 1,000 foot intervals.
The tunneling portion of the project and all the manhole construction work has been completed. The construction of the transition structures (at both the receiving and the launching shafts) located south of Bridgecross Drive and within the New Natomas Pump Station respectively, is also nearing completion. The next item of work taking place this fall is the final lateral connection of the existing sewer collection system to UNWI 1 & 2 and final site restoration.
Minimum traffic controls may be needed during construction, please watch for construction crews and trucks entering and leaving the sites. UNWI 1 & 2 will be completed in the winter of 2010.
Project Background
The existing Sacramento Regional County Sanitation District (SRCSD) interceptor system in the northern and eastern part of Sacramento County is nearing capacity and is at risk of overflow during severe wet weather. Once UNWI 1 & 2 is completed, the entire UNWI system will eliminate the risk of overflows and ensure both present and future sewer capacity needs are met in accordance with the County's general plan for growth.
The UNWI interceptor system is divided into nine sections in order to promote efficient management and construction activities; Section 1 starts in Natomas and Section 9 ends in Citrus Heights.
Sections 3 through 8 are now complete. Sections 1 & 2 and Section 9 are the last sections under construction. Once completed, the entire UNWI system will convey wastewater from the existing collection systems starting in Citrus Heights and Orangevale and ending in Natomas. From Natomas, the wastewater will be conveyed to the Sacramento Regional Wastewater Treatment Plant in Elk Grove via the existing Lower Northwest Interceptor.
UNWI 1 & 2 by the Numbers
- 19,300 feet of 144-inch pipe
- 84-inch by 144-inch transition structure to connect UNWI Sections 1 & 2 and 3 & 4
- 54 feet of 120-inch interceptor pipeline
- 20 manholes spaced 1,000 feet apart
- 3 connections to existing collection sewer lines
- 144-inch by 120-inch transition structure to connect UNWI Sections 1 & 2 to the New Natomas Pump Station
What to Expect During Construction
Construction Hours:
Construction crews extended construction hours at the UNWI 2 & 3 receiving shaft located south of Bridgecross Drive between Natomas Boulevard and Honor Parkway. Construction activities will not impact vehicular traffic on the street. Currently construction hours are:
Monday through Friday -- 7 a.m. - 5 p.m.
Bike Path Access
The bike path next to the East Drainage Canal may experience short-term closures. Construction crews will do everything possible to maintain a bicycle-friendly area, but it is the rider's responsibility to be aware of all construction activities. Please do not use closed areas of the bike path and always watch for construction traffic and construction-related debris. Your safety is important to us!
Driving Caution
During construction short term lane closures or traffic controls may be needed. Please watch for construction crews and trucks entering and leaving work zones.
Other Possible Impacts
Throughout construction, the project team will do everything possible to minimize impacts to the community. However, certain disruptions may be unavoidable, such as increased noise and dust and occasional lane closures and lane shifts.
Questions? Concerns?
We apologize for any impacts you experience and thank you for your continued patience and understanding. Maintaining communication with residents and businesses throughout the construction process is very important to the team. We encourage you to check this Web site for updated information. If you have any questions regarding this project or the upcoming work, please call our toll-free 24-hour hotline at (866) 479-0600. If you'd like to speak with someone regarding an issue or impact, please call 24-hour hotline at 866-479-0600.