Water Main Flushing

Description:

Water Main Flushing to Prepare for the Davis Woodland Water Supply Project
Beginning in Spring 2016, the City of Davis Public Works Department will be performing water main flushing to prepare the water system to receive treated water from the Davis Woodland Water Supply Project. This flushing program follows industry best practices to minimize the potential for red water (typically iron rust from galvanized iron, steel or cast iron pipes) that can occur when a new water supply scours the existing water lines. Red water is not a human health concern, but has the potential to stain laundry. It is anticipated that this water main flushing, while not completely removing the potential for red water as the new water supply is introduced, will reduce the likelihood and severity of red water occurrences.  Find out more information in the Source Water Integration Study (Trussell Technologies Report) commissioned by the Woodland Davis Clean Water Agency.


As a result of the current drought and restrictions on water use, the city’s water main flushing program has been on hold since 2013. Cleaning of water mains has historically been done by flushing water at high velocities through fire hydrants and required large volumes of water. To reduce water loss, the City of Davis will be using a NO-DES process (learn more here http://www.no-des.com) where two fire hydrants are connected through a dual filtering system. Once this loop is created, an onboard pump is used to reverse the normal direction of flow while ensuring the flow rate reaches a minimum of 5 feet per second. The high velocity reached by the onboard pump scours the main, removing any collected sediment. Flushing averages about 15 minutes for each hydrant. The filtered water is then pumped back into the water distribution system instead of draining to a storm drain minimizing the loss of potable water to the storm drain. A chemical metering pump is provided to maintain the distribution system’s target chlorine residual and periodic samples are taken to confirm that bacteriological safety is maintained.


Customers may notice some short term effects during this period, including slight pressure drops, air in the lines or discolored water during the flushing process.  The discoloration is temporary and typically clears within a few hours. It is recommended that residents check their water before use, especially prior to doing laundry, as laundry may become stained. If customers notice these effects, we recommend running cold water for a short time afterward to remove any loosened sediment in the pipeline, possibly saving the water for plants or other landscape needs.


If you have any additional questions, please e-mail PWWeb@CityofDavis.org or call (530) 757-5686.


Water Distribution System Flushing Plan Map


Tentative Water Main Flushing Schedule Update


Phase 1-6:  Completed


(Dates will be updated if the schedule changes - time required for flushing is highly variable depending upon pipe conditions).



  • 12/28/16-Water Main Flushing in South Davis

    The City of Davis Public Works Department will be performing water main flushing in South Davis to complete the Davis Surface Water Supply Project. A portion of the area was completed in the fall and … more

  • 5/11/16-Flushin Program Update

    Phase 1:  CompletedPhase 2:  CompletedPhase 3:  CompletedPhase 4:  CompletedPhase 5:  CompletedPhase 6: May 9 - May 23 more

  • 4/25 - Water Main Flushing Update

    Tentative Water Main Flushing Schedule Update

    Phase 1:  CompletedPhase 2:  CompletedPhase 3:  CompletedPhase 4:  CompletedPhase 5:  April 21 - May 2Phase 6:  May 3-11 more

  • 4/14 - Water Main Flushing Update

    Schedule Update:

    Phase 1:  CompletedPhase 2:  CompletedPhase 3:  CompletedPhase 4:  April 13 – May 4Phase 5:  May 5 – May 18 more

  • 4/5 - Water Main Flushing Update

    Updated Flushing Schedule:

    Phase 1:  CompletedPhase 2:  CompletedPhase 3:  April 4 – April 8Phase 4:  April 11 – April 29Phase 5:  May 2 – May 13 more

  • 3/28 - Water Main Flushing Update

    Phase 1:  Completed

    Phase 2:  March 24 – April 11

    Phase 3:  April 12 – April 21

    Phase 4:  April 22 – May 13

    Phase 5:  May 16 – May 2 … more

When: March 14, 2016 – June 15, 2016 (dates are approximate)

Where: Flushing will occur in 6 Phases in various areas of town (See map below)

Hours of Construction: Monday-Friday, 7am-6pm.

Traffic Impact: None

Funding: Surface Water Project

Project Contact: PWWeb@CityofDavis.org or (530) 757-5686

Project Source: Other

When: March 14, 2016 – June 15, 2016 (dates are approximate)

Where: Flushing will occur in 6 Phases in various areas of town (See map below)

Hours of Contruction: Monday-Friday, 7am-6pm.

Traffic Impact: None

Funding: Surface Water Project

Description:

Water Main Flushing to Prepare for the Davis Woodland Water Supply Project
Beginning in Spring 2016, the City of Davis Public Works Department will be performing water main flushing to prepare the water system to receive treated water from the Davis Woodland Water Supply Project. This flushing program follows industry best practices to minimize the potential for red water (typically iron rust from galvanized iron, steel or cast iron pipes) that can occur when a new water supply scours the existing water lines. Red water is not a human health concern, but has the potential to stain laundry. It is anticipated that this water main flushing, while not completely removing the potential for red water as the new water supply is introduced, will reduce the likelihood and severity of red water occurrences.  Find out more information in the Source Water Integration Study (Trussell Technologies Report) commissioned by the Woodland Davis Clean Water Agency.

As a result of the current drought and restrictions on water use, the city’s water main flushing program has been on hold since 2013. Cleaning of water mains has historically been done by flushing water at high velocities through fire hydrants and required large volumes of water. To reduce water loss, the City of Davis will be using a NO-DES process (learn more here http://www.no-des.com) where two fire hydrants are connected through a dual filtering system. Once this loop is created, an onboard pump is used to reverse the normal direction of flow while ensuring the flow rate reaches a minimum of 5 feet per second. The high velocity reached by the onboard pump scours the main, removing any collected sediment. Flushing averages about 15 minutes for each hydrant. The filtered water is then pumped back into the water distribution system instead of draining to a storm drain minimizing the loss of potable water to the storm drain. A chemical metering pump is provided to maintain the distribution system’s target chlorine residual and periodic samples are taken to confirm that bacteriological safety is maintained.

Customers may notice some short term effects during this period, including slight pressure drops, air in the lines or discolored water during the flushing process.  The discoloration is temporary and typically clears within a few hours. It is recommended that residents check their water before use, especially prior to doing laundry, as laundry may become stained. If customers notice these effects, we recommend running cold water for a short time afterward to remove any loosened sediment in the pipeline, possibly saving the water for plants or other landscape needs.

If you have any additional questions, please e-mail PWWeb@CityofDavis.org or call (530) 757-5686.

Water Distribution System Flushing Plan Map

Tentative Water Main Flushing Schedule Update

Phase 1-6:  Completed

(Dates will be updated if the schedule changes - time required for flushing is highly variable depending upon pipe conditions).

Project Link: http://www.cityofdavis.org/city-hall/public-works/water/davis-water-quality-improvement-project

Contact: PWWeb@CityofDavis.org or (530) 757-5686