Tim Richardson, P.E. City of Olympia 601 4th Avenue E. Olympia

Transcription

1 October 17, 2014

2 Tim Richardson, P.E. City of Olympia 601 4th Avenue E. Olympia

3 City of Olympia McAllister Drinking Water Wellfield Project Historic Municipal/Tribal Partnership Secures Safe, Reliable Water Source for Current and Future Generations On October 4, 2014 over 100 community and tribal leaders, residents, contractors and staff gathered at the new McAllister Wellfield and raised glasses of fresh, clear well water to celebrate the project s completion. The celebration capped off a 20+ year of effort to develop a more protected and productive water source to meet water supply needs for generations to come.

4 Historic Municipal/Tribal Partnership The Nisqually River watershed is the historic water source of the Nisqually Indian Tribe. In contemporary times, it is also serves the cities of Olympia, Lacey, and Yelm, and adjacent areas of unincorporated Thurston County. A key component of the project was a collaborative, interjurisdictional partnership agreement. This multi-year effort, assisted by Ecology, involving the Nisqually Indian Tribe and the cities of Olympia, Yelm, and Lacey, resulted in a water right supply package that is the first of its kind in Western Washington. Instead of individual mitigation studies and activities, the partnership worked together on water use mitigation to achieve the greatest benefit for the watershed as a whole. In addition, the City of Olympia and the Nisqually Tribe signed an agreement to jointly develop a new regional water source at the McAllister Wellfield. This historic agreement is the first such agreement between a Tribe and a municipality in the Country. The agreement also formed a stewardship coalition to protect water resources in the Nisqually Watershed and provide permanent protection to McAllister and Abbott Springs. The McAllister Wellfield Project The $11.5 million McAllister Wellfield project included: 1. Drilling and developing three new water supply wells providing a total capacity of over 15,000,000 gallons per day; 2. Constructing three well houses equipped with pumps, a chlorination system, electrical controls, security system; and 3. Installing nearly one mile of 36-inch and 30-inch water transmission pipeline. To protect the pipeline, 360 feet of 54-inch diameter casing was installed under the Burlington Northern Railroad tracks and 306 feet of 48-inch diameter casing installed under Old Pacific Highway. Well PW-25 pump Drilling casing under railroad tracks for the transmission main The McAllister Wellfield replaces the City s existing water source, McAllister Springs, that provided over 80% of drinking water for the City of Olympia. The City relied on McAllister Springs for more than 60 years. 2

5 McAllister Springs Located at the headwaters of McAllister Creek, McAllister Springs continuously provides high-quality water but is vulnerable to potential contamination. The Springs location is vulnerable to potential contamination from a fuel or hazardous chemicals spill due to close proximity to the BNSF Rail line (immediately upgradient), a susceptibility to microbial contamination at certain times of the year due to the configuration of the Springs and adjacent pond, and salt water intrusion as sea levels rise. In addition, during dry summer months the City has reduced ability to use the full water right without affecting water quality. Due to upcoming federal regulations the Springs would require extensive additional treatment, if not retired within the next few years. Because of these concerns about the vulnerability of McAllister Springs and new regulations regarding the treatment of spring waters, Olympia made a decision to move its water production site from McAllister Springs to groundwater wells at an upgradient location. The new McAllister Wellfield is located about one mile southeast of McAllister Springs. The new McAllister Wellfield is one of the most prolific wellfields in the United States. The largest well (PW- 25) has a capacity of 6,900 gallons per minute (gpm) with a drawdown of less than 3 feet. Two wells were drilled in 1997 (TW-22 and PW-24) as part of the initial exploratory investigations for the Wellfield. Both wells had rehabilitation work done in 2012 to be able to bring them into production. Drilling the large well PW-25 began in 2012 and was completed in The wells are approximately 400 feet deep and 12-inch, 20-inch, and 24-inch diameter. Combined, the three wells can produce up to 10,500 gpm. The City has water rights to withdraw up to 16,000 gpm from the Wellfield, so the transmission and treatment facilities have been sized to accommodate construction of an additional 5,500 gpm well in the future. The three new wells have the equivalent pumping capacity of the Springs. The change in water right allows for additional phases in 2030 and 2050 to provide additional capacity as the need grows with the community. At full build out the Wellfield capacity will increase by 5,500 gpm, which is an additional 7.9 million gallons per day. Developing Well PW-24 3

6 Completion Date Originally the project substantial completion date was July 30, Despite an 80 day suspension due to delays in fabrication and delivery of the large capacity well pumps, the project was finished on time for the Wellfield Dedication Ceremony on October 4, thanks to a dedicated effort between the City, our contractor Rotschy, subcontractors, and Gray & Osborne. During the suspension period, the contractor worked on the electrical systems in anticipation of the pump arriving, to shorten the time it would take for the pumps to be connected and operational. The project was substantially complete October 17, After this the entire facility went through a one month period for system start up, testing and commissioning. The electrical systems, telemetry, chlorination system, valves, and pumps were all tested to make sure they were all working correctly. As issues arose they were resolved. On November 20, 2014 the Wellfield was turned on and began supplying water to the City. The project was successfully completed on schedule. 4

7 Construction Schedule, Management and Control Techniques Used Construction Timeline: August 13, 2012 April 10, 2013: Transmission main construction. September 4, 2012 February 7, 2013: Well drilling. November 4, 2013 October 17, 2014: Construction of the well buildings and chlorination facility with all piping and accessories. November 20, 2014: The City transitioned water supply from McAllister Springs to the new McAllister Wellfield Facility. During construction, a unique web-based Construction Management System was used to facilitate communication between the City s project team, Gray & Osborne s project team, and Rotschy, the contractor. This system, developed by Gray & Osborne, acted as a repository for all project documentation including the contract, submittals, RFIs, change orders, progress payments, and certified payrolls. The system greatly reduced traffic and allowed all project members to stay up to date with the status of submittals and RFIs and provide input prior to decisions being made. It was an invaluable tool for maintaining good communication throughout the project. The City of Olympia and Gray & Osborne provided collaborative construction management and inspection of the project. City staff led the construction management team and provided daily construction inspection, prepared progress pay estimates and change orders, reviewed submittals and prevailing wage and certified payroll documentation. Gray & Osborne staff reviewed submittals, RFIs, and change order proposals; and managed start-up, testing, commissioning, and training activities. Both City and Gray & Osborne staff participated in weekly or bi-weekly construction meetings. 5

8 Safety Performance The McAllister Wellfield project had an outstanding safety record. Over 14,500 hours were worked with no lost time injuries during the project. The City required the general contractor and its subcontractors to develop and comply with a project specific safety program. The general contractor, Rotschy, Inc., and its subcontractors demonstrated a high regard for implementing best safety practices and held weekly safety meetings throughout the project to review safety issues and protocols. Some of the safety risks that can be encountered when constructing this type of facility include using heavy equipment including large drill rigs and earth moving equipment, walking and standing on scaffolding to construct the buildings, working around high voltage equipment, working on the roof of the buildings, and working in trenches that require shoring. Construction of the 36-inch transmission main required boring under the main North/South BNSF Railroad tracks situated on a 30 foot embankment. The 36-inch pipeline was installed within a 54-inch steel casing that was another 20 feet below grade. The workers and boring equipment were protected from cave-ins by shoring. The railroad was monitored for movement in case vibration from the work caused the rails to subside. At one point a slight sink hole was noticed on the opposite side of the tracks as the casing was being pushed. The small sink hole did not get worse and was determined to not be a risk to the rails or the construction of the casing. Installing the screen in Well PW-25 Installing the 36-inch transmission main Construction of the Well PW-25 Building & Chlorination Facility 6

9 Environmental Considerations Since the McAllister Wellfield is intended to be the City s primary long-term water supply source, during construction the City and the contractor took special care in working around the well heads. All construction equipment was inspected for fluid leaks prior to being used on site. Equipment on site was required to park outside of the 100-foot sanitary control area. Drip pans were placed under vehicles to prevent any potential contamination of the aquifer. Erosion control best management practices were used to prevent sediment laden run-off from leaving the site. Erosion control measures implemented included silt fence, straw wattles, biobags, straw, mulch, and hydroseeding. The site was seeded and stabilized prior to winter rains arriving. Well discharge swales were also seeded and established well in advance of the Wellfield being completed to ensure that water discharge from the wells would not cause erosion. A multi-year collaborative effort, assisted by the Washington State Department of Ecology, involving the cites of Olympia, Yelm, and Lacey, and the Nisqually Indian Tribe resulted in a water right supply partnership that is the first of its kind in Western Washington. Each jurisdiction coordinated mitigation efforts as part of their own water source development activities to provide the greatest benefit for the watershed as a whole. The cooperation shown by Olympia and the other jurisdictions on the water rights is likely going to be the wave of the future, per Mike Gallagher, Department of Ecology. The water right permits include extensive environmental protections for fish-bearing streams and other area water bodies in the form of mitigation. McAllister Creek City of Olympia s water right transfer moves water use away from McAllister and Abbott Springs to the nearby McAllister Wellfield. This will increase surface water discharge at the Springs and stream flow in the creek. Salmon runs will be enhanced. Lake Saint Clair Mitigation for Lake St. Clair consists of acquisition and retirement of a surface water right within Eaton Creek which drains to the lake. Deschutes River Olympia, Yelm and Lacey are jointly providing mitigation on the Deschutes River by purchasing and retiring two water rights. The 197-acre Smith Ranch and its irrigation water rights are near Lake Lawrence, south of Yelm. The water rights will be retired to help offset the effects that new city wells will have on Deschutes River stream flows. The property includes over one mile of frontage along the Deschutes River for mitigation and restoration. Land will be preserved, habitat restored, wetlands created, and stream channels enhanced for fish. Restoration activities are ongoing. Woodland Creek Jointly constructed by the cities of Olympia and Lacey, the Woodland Creek Groundwater Recharge Facility is using reclaimed water to recharge groundwater that provides base flow to Woodland Creek. An additional 30 acres of undeveloped riparian property has been purchased in the Woodland Creek basin that will be protected from future development. Nisqually River Although minimum flows will not be affected in the Nisqually River due to river flow being controlled by Alder Dam, the Nisqually Tribe has adopted a groundwater ordinance on the reservation, will relocate shallow wells near the river, and will also invest in ongoing riparian improvements in the Muck and Ohop Creek areas. 7

10 In addition, the City and the Nisqually Tribe formed a partnership. They agreed to jointly develop a new regional water source at the McAllister Wellfield. The site is a more protected and productive water source for both the Tribe and the City. A stewardship coalition formed out of the agreement will protect water resources in the Nisqually Watershed and provide permanent protection to the McAllister Springs and nearby Abbott Springs. The City conducted a baseline study as part of the research to determine any impacts to the regional water bodies. The City did extensive regional water level testing to determine if there were impacts to ground water and surface waters in the region. The City installed numerous monitoring wells and staff gauges, coordinated with homeowners and local agencies to monitor water levels during testing. The City used the information in a computer model to predict surface water and groundwater level changes. The City also conducted an extensive study of Lake St Clair to determine if pumping wells in the new Wellfield would impact water levels in the lake. To protect the new water source from potential sources of contamination, the City purchased the 20 acre Wellfield parcel, a 66 acre parcel directly upgradient of the Wellfield, and purchased development rights for the surrounding 100 acres. These areas will be left as is, in pasture grass and forest. Community Relations McAllister Springs has been the main source of water supply for the City of Olympia for 66 years. Located at the headwaters of McAllister Creek, the area has a rich cultural history. It served as a vital resource for thousands of years first by the ancestors of the Nisqually Tribe and continuing through Euro-American settlement to the present day. The City entered into a historical agreement with the Nisqually Tribe to jointly develop a regional water source, to form a stewardship coalition to protect water resources in the Nisqually Watershed, and to provide permanent protection to McAllister and Abbott Springs. Historic partnership signing with Olympia Mayor Doug Mah and Nisqually Tribe Chairperson Cynthia Iyall Together, the City and the Nisqually Tribe held a ceremony to Honor the Springs. The Nisqually Tribal community has a special relationship with water and especially with McAllister Springs and Creek. The Springs are considered a sacred site, known historically as Medicine Creek. It was the site of the 1854 Treaty of Medicine Creek between the United States and the Nisqually and other tribes. Honoring the springs ceremony, Native Elder Blessing 8

11 A Wellfield Dedication Ceremony held on October 4, 2014 provided an opportunity for the community to see the new facilities and learn more about their new water source. The Nisqually Tribe performed a traditional blessing of the new Wellfield. The large pump on PW- 25 well was turned on and the Wellfield was operational. The City formed regional partnerships with the cities of Yelm and Lacey, and the Nisqually Indian Tribe to facilitate movement forward to transfer water rights from the Springs to a new Wellfield; obtaining water rights and providing the greatest benefit for the watershed as a whole. Along with developing regional partnerships, the City made significant community relations efforts throughout the 20 years of development and construction of the McAllister Wellfield Project. The City strategized a communications plan that included meetings with homeowners and informational publications, articles in local media outlets, and construction updates via social media and water bill inserts. The City also maintains a website with project information, history and updates ( drinking-water/mcallister.aspx#). City residents were invited to participate in a lake bottom study of Lake St. Clair. The City facilitated coordination between homeowners and local agencies in the region to monitor water levels in groundwater wells and surface water bodies during baseline testing. 9

12 The City also took great care to maintain good relationships with the surrounding property owners. The City purchased the 20 acre Wellfield parcel from the Thomsen family along with development rights for the surrounding 100 acres to protect the Wellfield from potential sources of contamination. As part of the agreement, the City agreed to make the well houses as small and unobtrusive as possible. The City complied with this condition in the design and construction of the well house buildings. Throughout the design and construction of the project, the City provided the Thomsen family with regular updates on the status of the project and the types of construction activities to expect. When activities could potentially impact the Thomsen s use of their roads or fields, the City maintained a respectful relationship with the family and worked with them well in advance of changes. McAllister Wellfield Buildings To ensure that the City s water customers would continue to enjoy the same high quality drinking water that they had with the McAllister Springs, the City completed extensive water quality testing on the Wellfield water prior to beginning construction. Water quality testing included the assessment of a wide range of physical/chemical properties and inorganic, volatile organic, synthetic organic compounds, as well as aesthetic considerations such as taste and odor. In addition to comparing the Wellfield water to the water from the existing McAllister Springs source, the City completed the assessment of a number of representative blends of Wellfield water with water from other City sources to confirm that there would be no adverse impacts. Unusual Accomplishments under Adverse Conditions Prior to design of the McAllister Wellfield, the City completed assessment of the two wells (TW-22 and PW-24) that had been drilled in Although PW- 24 appeared productive and in good condition, it produced excessive sand. With the oversight of Golder Associates, the City hired Holt Services, Inc. to conduct additional well development. This work reduced sand production from the well, but it still was sanding excessively. Golder then used a dynamic spinner log and video camera to determine that most of the flow and associated sand production was occurring in the upper most 10 feet of the well screen. To correct this problem, a segment of blank casing was installed in the upper 10 feet of the screen to stop sand contribution from this area. Additional well development was then performed until the sand production was reduced to acceptable levels. Completing the additional well development and well modifications allowed the City to put PW-24 into production instead of having to drill an additional well. The cost to further develop PW-24 was approximately $150,000 versus an estimated cost of $260,000 to drill and develop a new well. This resulted in a savings to the project of approximately $110,

13 Due to the size and capacity of the well pumps, there were few available vendors that could supply the pumps. The vendor that was selected to supply the pumps to the general contractor had offices worldwide, with factories based in Mexico. The vendor had issues associated with communication between its offices and manufacturing of the pumps, therefore delivery of the pumps was delayed for several months. The pumps did not arrive on-site until September 16, With our Wellfield Dedication ceremony scheduled for October 4, it was especially important to have the large well operational for the event. The contractor had only 18 calendar days to install the well pumps; complete installation of discharge piping and valves; install wiring, instrumentation, and controls to all three pumps; complete start-up; finish all three well buildings; and do site cleanup. It was a complete team effort between the City; our contractor, Rotschy; the subcontractors; and Gray & Osborne to complete the work for the Dedication Ceremony and finish the project on schedule. McAllister Wellfield Dedication Ceremony- Nisqually Tribe Chairperson Cynthia Iyall and Olympia Mayor Stephen Buxbaum 11