To: Members of the Castle Rock Water Commission
From: Mark Marlowe, P.E., Director of Castle Rock Water
Title
Regional Wastewater in Northwest Douglas County
Town Council Agenda Date: NA
Body
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Executive Summary
Castle Rock Water (CRW) is working with Douglas County, Dominion Water and Sanitation District (Dominion), and the Plum Creek Water Reclamation Authority (PCWRA) on a potential regional wastewater project that would serve the Highway 85 corridor through Northwest Douglas County (see Attachment A). The Highway 85 corridor does not currently have a viable economic means to warrant central wastewater infrastructure without County investment. However, using the County’s current financial capacity, Dominion’s existing regional water and wastewater infrastructure, Castle Rock’s existing regional water infrastructure and extensive operational capabilities, PCWRA’s extensive operational capabilities and experience, there is an opportunity to provide regional service to communities needing it now. This opportunity is made possible through the development of regional infrastructure by the three water and wastewater providers, a long-standing partnership between Dominion and Castle Rock, and financial resources coming available to the County through the American Rescue Plan Act (ARPA). The primary benefits to CRW of this partnership include:
1. Access to purchase reusable wastewater supplies from existing water use in the corridor today that could then be reused in Castle Rock to extinction.
2. Option to purchase future reusable wastewater supplies from new development that may occur in the corridor as a result of centralized wastewater that could then be reused in Castle Rock to extinction.
3. Ability to create economies of scale for our operations which will help keep costs competitive for our customers in Castle Rock.
4. Generation of extraterritorial surcharges that could benefit CRW’s operational costs in Castle Rock.
5. Strengthening of regional partnerships for water and wastewater infrastructure which partnerships reduce long term infrastructure costs benefiting our customers.
6. Protection of water quality in Chatfield Reservoir, a key long term drinking water reservoir for CRW.
Castle Rock will not put any financial investments into the proposed project. All of the infrastructure investment to the tune of approximately $30M would be paid by Douglas County if the project moves forward. The infrastructure constructed would then be dedicated to CRW to own and operate.
Discussion
Douglas County has identified a need to provide centralized wastewater along the Highway 85 corridor. Currently, there is no centralized wastewater in the corridor. Existing commercial, industrial and residential uses are served by septic tanks, many of which are failing, and in at least one case a failing wastewater lagoon system. Centralized wastewater is needed to clean up Plum Creek by providing an option for properties on failing septic tanks or connected to old failing wastewater lagoon systems to connect to a centralized system. Having a centralized system will also ensure that additional development does not occur in the corridor off of septic systems. Centralized wastewater will allow for future economic development along the corridor including higher value and denser commercial and industrial uses that will provide primary jobs for County (and potentially Castle Rock) residents as well as higher density residential development. Centralized wastewater will provide for more robust treatment than septic systems and is needed to help clean up water quality in Plum Creek and protect water quality in Chatfield Reservoir. Chatfield Reservoir, a drinking water supply for Castle Rock and much of the front range, did not meet water quality standards in 2020 and those standards are expected to only tighten in future years.
Key aspects of CRW’s involvement would include:
• Own and operate the Highway 85 collection system infrastructure. Castle Rock would not take on any land use authority with this responsibility. System development fees and or a small percentage of customer revenues would be collected and returned to County to help pay back some of the County’s initial investment. All wastewater return flows not purchased by Castle Rock will remain under the control and ownership of the entity that generated the wastewater within the Highway 85 collection system infrastructure.
• Serve as the retail provider of water and wastewater services for interested customers in the Highway 85 corridor for an appropriate fee including for existing small water and sanitation districts, allowing them to dissolve if desired. Water customers will be required to comply with conservation and sustainability requirements of Dominion at a minimum and any others required by Castle Rock to ensure uninterrupted retail service.
• Set retail rates in accordance with cost of service utilizing the same basic approach and model used for Castle Rock’s existing customers but utilizing the actual infrastructure, wholesale rates, and other applicable costs for the new service area. Castle Rock would include a 10% extraterritorial surcharge consistent with other extraterritorial services provided by Castle Rock.
• Potentially provide contract operations for Dominion’s wholesale water and wastewater facilities, as agreed to between the entities.
• Partner with Dominion in raw water and return flow infrastructure from the Chatfield Basin Water Reclamation Facility (CBWRF) site to support reuse and sustainable water supply within Douglas County.
• Partner with Dominion to provide project management and engineering services to Douglas County for the design and construction of the infrastructure at a cost to the County of approximately 1% of the capital cost.
Budget Impact
The budget impact to CRW should be positive, but until full details of the project have been identified this aspect cannot be fully evaluated.
Attachments
Attachment A: Map