Loading...
HomeMy WebLinkAboutStaff Report 3.E 01/07/2019DATE: January 7, 2019 Agenda Item #. TO: Honorable Mayor and Members of the City Council through City Manager FROM: Dan t F. E —Director, Public Works and Utilities Leah odsey Walker, P.E. — Environmental Services Manager SUBJECT: Resolution Approving Award of a Bid to Advanced Water Treatment Technologies for Tertiary Pond Modular Floating Cover in the Amount of $66,644.50 RECOMMENDATION It is recommended that the City Council adopt the attached Resolution Approving the Award of a Bid to Advanced Water Treatment Technologies for Tertiary Pond Modular Floating Cover in the Amount of $66,644.50. BACKGROUND The City's Ellis Creek Water Recycling Facility (ECWRF) has been in operation since early 2009 and currently processes an average dry weather daily flow of 4.4 million gallons per day. A portion of the effluent receives further treatment by filtration and disinfection to produce tertiary - treated recycled water that is approved for non -potable uses. In 2017, ECWRF produced 562 million gallons of recycled water, 26% of the total annual influent flow, and distributed it for irrigation of agriculture, golf courses, landscaped areas at schools, parks, and other open space properties within the City, and for irrigation and process water at the ECWRF. The tertiary -treated water is stored in an uncovered 1.5 -million -gallon lotus shaped storage pond, with a clay bottom and concrete sloping sides. The unusual pond shape creates an inviting water feature that is surrounded by a conservation garden. However, exposure to waterfowl and sunlight negatively degrades water quality from its intended use due to photosynthesis and bird excrement. The organic material degrades the bacterial quality of the water and photosynthesis encourages the growth of aquatic plants. Algae, decomposing organic material and plant debris routinely clog pumping and irrigation equipment which increases maintenance costs. Normally recycled water storage reservoirs are either enclosed or covered to preserve water quality. Full enclosure of the pond was considered however, the curved shape of the pond makes retrofitting a structural cover difficult. DISCUSSION Several pond cover systems were investigated but due to the irregular shape and sloped side walls of the pond, conventional cover options, such as a rigid frame structure or floating flexible sheets were considered cost prohibitive. Floating "shade balls" were investigated but found to leave a significant amount of the pond surface uncovered when pushed by wind to the edge of the reservoir. In addition, surface contaminants are deposited into the water when the balls rotate. Hexagonal -shaped floating elements were developed by the industry to overcome these deficiencies. They improve stability and increase surface water coverage. The shape allows the elements to butt tightly against each other, creating a semi-rigid structure with a low wind profile. The modular floating design allows the cover to adjust to variable pond area as water levels change up and down, and to adapt to the irregular shape of the storage pond. Each element is approximately eight to twelve inches in diameter, made of hard plastic with a hollow core for buoyancy, and has a life expectancy of at least 20 years. This type of floating cover is expected to eliminate contamination from waterfowl and reduce the growth of vegetation in the pond. Prior to installation, operators will reduce the water level in the pond, remove as much vegetation as possible, and clean the concrete sides. In addition, the pond will be fenced to increase safety and discourage geese. An invitation to bid was circulated for a tertiary pond modular floating cover specifying 27,500 square feet of hexagonal floating elements with additional five percent surplus elements. The product will ship to ECWRF and be installed by City staff. The invitation to bid, including shipping and taxes, was sent to known suppliers of suitable products. Three quotations were received as shown below: Supplier Bid 1. Advanced Water Treatment Technologies, Texas $ 66,644.50 2. JT Covers, Iowa $ 76,062.58 3. Lemna Environmental Technologies, Minnesota $110, 435.00 Engineer's Estimate: $ 80,000.00 Because of the innovative nature of this product, a limited response was expected. A rigorous testing process was used on samples of the products to evaluate the durability and performance. All products passed the testing. The product submitted by Advanced Water Treatment Technologies has been in use at Napa Sanitation District for several years with good results. The lowest responsible bidder was determined to be Advanced Water Treatment Technologies located in Harlingen, Texas, at a price of $66,644.50. The price for the floating cover was determined to be reasonable and in-line with costs estimated from market research. It is recommended that Council approve the purchase. This action supports the City Council goal "Design and deliver cost-effective energy and other resource savings projects for City facilities and infrastructure." FINANCIAL IMPACTS The cost of purchasing the floating cover was anticipated in the Fiscal Year 18/19 budget for ECWRF Operations cost center within the Sewer Fund. The proposed action is currently budgeted and therefore will not cause any unanticipated fiscal impacts. Minor maintenance savings are anticipated as a result of reduced algae and debris fouling pump screens and accumulating in the pond. ATTACHMENTS 1. Resolution Attachment 1 RESOLUTION APPROVING AWARD OF A BID TO ADVANCED WATER TREATMENT TECHNOLOGIES FOR TERTIARY POND MODULAR FLOATING COVER IN THE AMOUNT OF $66,644.50 WHEREAS, a 1.5 -million -gallon storage pond at the Ellis Creek Water Recycling Facility (ECWRF) provides essential storage for tertiary -treated recycled water; and WHEREAS, the storage pond is uncovered leading to water quality degradation and increased maintenance; and WHEREAS, a modular floating cover was determined to be the best alternative for covering the tertiary recycled water storage pond at the ECWRF; and WHEREAS, a bid for a modular floating cover for the tertiary recycled water pond was publicly bid on October 18, 2018, and three (3) bids were received on November 8, 2018 in accordance with applicable law; and WHEREAS, Advanced Water Treatment Technologies provided the lowest responsible bid for the modular floating cover; and WHEREAS, the City Council budgeted funds in Fiscal Year 18/19 to purchase the modular floating cover. NOW, THEREFORE, BE IT RESOLVED that the City Council of the City of Petaluma hereby authorizes the City Manager to award the bid to Advanced Water Treatment Technologies for tertiary pond modular floating cover for an amount not to exceed $66,644.50. L!