|By: Lee Anne Jones, CH2M
Lee Anne presented her paper, “Commissioning Of The 1,375 ML/D Lakeview WTP High Lift Pumping Station – Much More Than Just A Pump Start And Stop Exercise,” co-authored by CH2M’s Ken Mains, Scott Crawford and Matt Richie, the Region of Peel’s Jeff Hennings and HydraTek’s Djordje Radulj, at the American Water Works Association’s Annual Conference and Exposition (ACE), on Tuesday, June 21, at 11 a.m.
|The Region of Peel currently serves more than one million consumers in the Greater Toronto Area (Canada) and supplies water through a purchase agreement to neighboring municipalities through two water treatment plants (WTP), Lakeview and Lorne Park. The Lakeview WTP, named Water Project of the Year in 2015, began operations in 1954 as a two-filter, 9 ML/D facility and was expanded as part of a regional water treatment and conveyance infrastructure expansion plan to provide capacity of 1,100+ ML/D.
Additional high lift pumping capacity was provided through the extension of the recently completed High Lift Pumping Station, with a new pump bay, consolidating all high lift pumping in a single station. The station is now capable of a pumping capacity of 1,375 ML/D to dual pressure zones, a local and elevated pressure zone. The elevated pressure zone functions primarily as a water transmission system with limited offtakes.
The station provides space for 15 pumps, seven existing, five new and refurbished pumps added under this expansion and space for three to be added in future. The pumps are all horizontally split, double-suction, bottom/side centrifugals driven by constant-speed motors. With sustainability in mind, the station is designed so that warmth generated from pump motor cooling water is re-used for building heat or dissipated into the pumped water, minimizing the need for additional cooling infrastructure.
In early 2015, commissioning commenced on the three pumps discharging into the elevated pressure zone. The pumps are rated at 150 ML/D in the 105-110 meter operating head range and are driven by 3,000-4,000 HP TEWAC motors. In addition to traditional commissioning activities that confirm equipment and controls operations, E-stop testing was carried out to simulate (under controlled circumstances), the consequences of unintended shut-down of the pumps and subsequent reverse velocities in the pipelines, which could happen if the utility lost power at the site. This testing allowed for the adjustment and fine-tuning of equipment, including check-valves and surge tanks, which are critical during emergency situations for reliable station operations.
When check valve slam and subsequent elevated transient pressures were suspected as a potential cause of a coupling failure during the testing of the first pump, high frequency (100 Hz) transient pressure monitoring was employed as an investigative tool to aid in the identification of remedial actions.
The transient analysis revealed significant transients as a result of check valve slam and successive tests were undertaken to evaluate optimization of the check valve closing time and ensure that resulting pressures were within the operating tolerances of the system for this emergency condition.
While unrelated equipment issues caused delays in completing the successive tests, the pumping station is now operational providing the Region with full flexibility leading into the peak summer flow season.
Throughout the commissioning of the Lakeview WTP, the team learned several important lessons, including the importance of a team approach and taking a multitude of stakeholders into account; the need for safety first, ensuring equipment failure did not result in physical injury to plant operators; and repair and replacement of equipment takes time because each component is highly complex.
For more details on the results of transient pressure profiling, the conclusions and impacts of equipment modifications during the commissioning of the three pumps and the challenges encountered coordinating and integrating the start-up of a facility with the magnitude and complexity of the Lakeview WTP High Lift Pumping Station, connect with Lee Anne Jones at this year’s AWWA ACE conference! Not at ACE? Follow the hashtag #ACE16.
Lee Anne Jones is a senior project manage in CH2M’s Toronto, Canada, office, with 25 years of both private and public sector experience. A Vice President in CH2M’s Water Business Group, she is Geographic Market Lead for the Greater Toronto Area. Lee Anne has been an AWWA member since 1994, and served as president of the Ontario section in 2011-2012. Lee Anne has managed multidiscipline project teams through all stages of multi-year water and wastewater projects, from planning through design, construction and commissioning.