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Home My WebLink About5.a. Splash Pad Water Re-Use EXECUTIVE SUMMARY Utility Commission Meeting: January 25, 2016 AGENDA SECTION: AGENDA ITEM: Splash Pad Water Reuse Old Business AGENDA NO. 5.a. PREPARED BY: Mitch Hatcher, Project Engineer ATTACHMENTS: Central Park Splash Pad Water Reuse Assessment Tech Memo, 2014 and 2015 APPROVED BY: pw Erickson Pond Monitoring Data, Vermillion River Watershed Letter RECOMMENDED ACTION: Discussion BACKGROUND On December 14, 2015 the Utility Commission discussed the water use at the Central Park Splash Pad. Water use for 2015 at the Splash Pad in 2015 exceeded 11 million gallons (MG). In relation to the water use, re-use options have been re-examined for the Splash Pad. The attached Central Park Splash Pad water re-use assessment was conducted in February of 2014 during the design phase of the Splash Pad project. At that time, the recommendation was to construct a flow- through system that drains the water used in the Splash Pad to Erickson Pond via the storm sewer system and this option was implemented with the Splash Pad project. It was noted that water levels at Erickson Pond be monitored to determine if additional action is needed. Since the Splash Pad has been operational, water levels in Erickson Pond have been monitored. The monitoring results from 2014 and 2015 are attached. The 2014 and 2015 Erickson Park monitoring data shows the daily rise and fall of the water level in Erickson Pond when the splash pad is in operation. There is no indication of a loss of storage capacity in Erickson Pond from the splash pad effluent, and the splash pad water is infiltrated in Erickson Pond. Erickson Pond consistently returns to the starting water elevation within 12 hours. Based on the splash pad water infiltrating within 12 hours, Erickson Pond does not have excess available water to be used for irrigation purposes. The flow-through system with irrigation re-use from Erickson Pond (Option 3.C.1) is not a feasible as the water levels would be reduced in Erickson Pond and possibly depleted during dry weather periods. The flow-through system with irrigation re-use from a storage tank (Option 3.C.2) could be considered. However, the initial cost of the storage tank and irrigation system is significant. This option includes the installation of underground storage tanks and modifications to the existing irrigation system at Erickson and Central Park. The estimated 2014 improvement cost was $276,000, with an annual operating cost of $13,740. The $13,740 is the estimated cost of the water utilized by the Splash Pad. The Splash Pad water reused for irrigation, estimated to be 5.5MG per year, would result in an estimated annual savings of $14,300 at the 2016 irrigation water rate of $2.60 per 1,000 gallons. A simple life cycle cost analysis was conducted to evaluate the benefit of the project. With the initial improvement cost now estimated to be C:\\Users\\klk\\AppData\\Local\\Temp\\20160125 UC Splash Pad Water Reuse_342562\\20160125 UC Splash Pad Water Reuse.docx $293,000 in 2016 dollars and an annual savings of $14,300, the break-even point is after the 20th year of operation. The recirculation system (Option 1) could also be a consideration. With this option, there are several unknowns including the certified staff that is required to operate and maintain the system and the retrofit design and construction. The estimated 2014 cost of the system was $258,000, with an annual operating cost of $16,600 which includes water, electric and chemical usage charges and projected maintenance. The expected water usage in the Splash Pad recirculation system is approximately 97% less than the current water usage. The water savings based on the 11MG per year, would result in an estimated annual savings of $27,700 at the 2016 irrigation water rate of $2.60 per 1,000 gallons. A simple life cycle cost analysis was conducted to evaluate the benefit of the project. With the initial improvement cost now estimated to be $274,000 in 2016 dollars and a net annual savings of $24,800, the break-even point is after the 11th year of operation. The recirculation system requires a pool certified and licensed operator and more daily monitoring and management of the system. The staff time and costs associated with this is largely unknown at this time. The cost estimates above are based on the information currently available. When the original estimates were completed it was assumed that the design and construction would take place concurrent with the Splash Pad. These improvement options would now be a retrofit to the existing Splash Pad, and there are several unknowns associated with that. If either option is considered, staff recommends that a feasibility study be completed in order to properly evaluate the options. Contact has been made with the Vermillion River Watershed to explore the option for possible grants and funding assistance. If awarded, a potential grant would fund up to 50% of the cost of the project. A letter showing the correspondence with the Vermillion River Watershed has been attached. The payback periods for these projects are very lengthy at over 11 years for the recirculation system and over 20 years for the irrigation reuse. The Vermillion River Watershed may be interested in providing a partial grant to fund the project and discussions are ongoing with the watershed officials. Should grant funding be achieved at a 50% level, the payback time would decrease by half. Staff recommends if a Vermillion River Watershed grant is available, the project is considered for implementation and a feasibility study conducted. SUMMARY Staff would like to initiate a discussion regarding the Splash Pad water reuse for irrigation and recirculation system projects and the potential Vermillion River Watershed grant funding. 2 ROS�MOLINT PUBLIC WORKS DEPARTMENT January 20, 201 G Mr. Mark Zabel- Administrator Vermillion River Wateshed 14955 Galaxie Avenue Apple Valley MN 55124 Re: Rosemount Splash Pad Water Reuse - VRWJPO Grant Availability Engineering Project 0185 Dear 1�1ark: Thank you for the opportunity to discuss the possibiliry of Vermillion River Watershed Grant funding for the water re-use project at the Rosemount Splash Pad. The Rosemount Splash Pad used appro�mately 11,000,000 gallons of water in 2015. This water is collected in a drain tile system which is connected to a nearby storm sewer and conveyed to Erickson Pond approximately 350 feet to the northwest. The flow through system to Erickson Pond is discussed as option 3.�� on the attached Technical l�7emorandum for the Central Park Splash Pad Reuse Assessment. This oprion was chosen as it had the lowest upfront cost for construction. Recently, there has been a renewed interest in re-purposing the water utilized bj- the Rosemount Splash Pad. The reuse discussions ha`�e centered on the direct contact Recirculation Sy�stem (option 1) and an Irrigation System with an Underground Storage Tank (Option 3.c.2). The irrigation project would require the use of a tank rather than Erickson Pond to stoYe the collected Splash Pad water as level monitoring in Erickson Pond over the past two summers have shown that the�vater volume from the Splash Pad is fully infiltrated over the nighttime hours and unavailable for reutilization for irrigation the next day. The estimated cost for the storage tank irrigation system was $27G,000 in 2014. It was estimated that the reuse of the splash pad water for irrigation in I�rickson Park and Central Park could sa��e o�er 5 inillion gallons per year based on 2011 through 2013 water use reported in Tables 1 and 2 of the attached technical memorandum. Thank you for considering this project for Verrrullion Ri�-er funding possibilities. Please contact me at your convenience if you would like any additional information. Sincerely, � �_ Patrick Wrase, P.E. Director of Public Works/City Engineer Enclosure G:AL?NGPROJ\I?NG IIlK�-SPlash P�a�&I�:nckson Vond Stormoatcr Rcu.c\3111GI)1211 l,cttcr'/.nbcLdocs SPIRIT OF PRIDE AND PROGRESS 2875 145th Street West• Rosemount,MN 55068-4997•651-423-4411 •TDD/TTY 7-1-1 • Fax 651-322-2694 www.ci.rosemount.mn.us