Document Arvada_doc_f0d4b625fb

City of Arvada Source Water Protection Plan - Update Public Version Jefferson County, Colorado February 24, 2022 Written by Paul Hempel Source Water Protection Specialist, CRWA For the Community Water Provider: City of Arvada, PWSID# 130001 ---PAGE BREAK--- City of Arvada Source Water Protection Plan Primary Contact Information for City of Arvada PWS Name City of Arvada PWSID # CO0130001 Name Evelyn Rhodes Title Water Quality Administrator Address 8101 Ralston Road, Arvada, CO 80002-2439 Phone [PHONE REDACTED] Website Cover photo: City of Arvada Source Water Protection Areas, by Paul Hempel, CRWA This Source Water Protection Plan is a planning document and there is no legal requirement to implement the recommendations herein. Actions on public lands will be subject to federal, state, and county policies and procedures. Action on private land may require compliance with county land use codes, building codes, local covenants, and permission from the landowner. This SWPP for the City of Arvada was developed using version 16.09.09 of the Colorado Rural Water Association’s Source Water Protection Plan Template. ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 3 TABLE OF CONTENTS EXECUTIVE SUMMARY 6 9 Purpose of the Source Water Protection Plan 11 Background of Colorado’s SWAP Program 11 Source Water Assessment Phase 12 Source Water Protection Phase 12 SOURCE WATER 13 Location and 13 Hydrologic Setting 15 DRINKING WATER SUPPLY OPERATIONS 16 Water Supply and 16 Water Supply Demand 26 SOURCE WATER PROTECTION PLAN DEVELOPMENT 27 Stakeholder Participation in the Planning 27 Development and Implementation Grant 29 Source Water Assessment Report Review 29 Defining the Source Water Protection 29 Inventory of Potential Contaminant Sources and Other Issues of 33 Priority Strategy of Potential Contaminant Sources and Other Issues of Concern 33 DISCUSSION OF POTENTIAL CONTAMINANT SOURCES AND ISSUES OF CONCERN 37 SOURCE WATER BEST MANAGEMENT PRACTICES 51 EVALUATING EFFECTIVENESS OF SOURCE WATER PROTECTION 57 58 APPENDICES 59 ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 4 FIGURES Figure 1: Page 9 Schematic Drawing of the Potential Sources of Contamination to Surface and Groundwater Figure 2: Page 10 Location of City of Arvada Within Colorado Figure 3: Page 10 Location of City of Arvada in Denver Metro Region Figure 4: Page 11 Source Water Assessment and Protection Phases Figure 5: Page 14 Land Ownership within the Clear Creek Watershed Figure 6: Page 14 Elevation within the Clear Creek Watershed Figure 7: Page 14 Precipitation within the Clear Creek Watershed Figure 8: Page 15 Big Picture Hydrology of City of Arvada’s Water Sources Figure 9: Page 15 Local Hydrology of City of Arvada’s Water Sources Figures 10-12: Page 16 Ralston Reservoir Figures 13-16: Page 17 South Boulder Diversion Canal Figure 17: Page 17 Ralston Creek Diversion Location Figures 18-19: Page 18 Ralston Creek Diversion Structure Figure 20: Page 18 Ralston Reservoir and Upper and Lower Long Lakes Figure 21: Page 19 Church Ditch Diversion off Clear Creek Figures 22-24: Page 20 Farmers Highline Canal Diversion off of Clear Creek Figure 25: Page 20 Croke Canal Headgate at Coors Plant Figure 26: Page 21 Church Ditch Diversion and Pump Station Figures 27-30: Page 21 Church Ditch Diversion Figure 31: Page 22 FHL Headgate at Golf Course Figure 32-33: Page 22 FHL Diversion and Holding Pond Figure 34 Page 23 Croke Canal Diversion and Pump Station Location Figures 35-26: Page 23 Croke Canal Diversion and Pump Station Figure 37: Page 24 Arvada Reservoir and Surrounding Infrastructure Figures 38-41: Page 24 Arvada Reservoir Figure 42: Page 25 City of Arvada Water Infrastructure Big Picture Figure 43: Page 25 Water System Diagram Figure 44: Page 31 City of Arvada SWPAs Figure 45: Page 32 Ralston Reservoir SWPAs Figure 46: Page 32 Arvada Reservoir SWPAs Figure 47: Page 34 CRWA’s SWAP Risk Assessment Matrix Figure 48: Page 38 City of Arvada Golf Course Area Nutrient Sampling Locations Figure 49: Page 38 Croke Canal Diversion, Pump Station and Sampling Location Figure 50: Page 39 Croke Diversion Sampling Location at Arvada Reservoir Figure 51-52: Page 39 Croke Canal Total Nitrogen and Total Phosphorus Concentrations Figure 53: Page 40 FHL Diversion and Sampling Locations Figure 54-55: Page 40 FHL Total Nitrogen and Total Phosphorus Concentrations Figure 56: Page 41 Church Diversion and Sampling Location Figure 57: Page 41 Church Conduit Outlet and Sampling Location Figures 58-59: Page 42 Church Diversion Total Nitrogen and Total Phosphorus Concentrations Figure 60: Page 43 Zebra and Quagga Mussel Sightings Distribution Figure 61: Page 44 Eurasian Watermilfoil Figure 62: Page 45 Schwartzwalder Mine Figure 63: Page 48 Clear Creek Watershed WUI Figure 64: Page 49 Lower Clear Creek Watershed WUI Figure 65: Page 49 Lower Clear Creek Watershed Wildfire Risk ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 5 Figure 66: Page 50 Clear Creek Watershed Drinking Water Importance Areas Figure 67: Page 51 Lower Clear Creek Drinking Water Risk TABLES Table 1: Page 16 Surface Water Supply Information Table 2: Page 27 Planning Meetings Table 3: Page 28 Stakeholders and Steering Committee Meetings Table 4: Page 35 Potential Contaminant Sources and Issues of Concern Prioritization Table 5: Page 53 Best Management Practices COMMON ACRONYMS ANS Aquatic Nuisance Species BMP Best Management Practice CDOT Colorado Department of Transportation CDPHE Colorado Department of Public Health and Environment CPW Colorado Parks and Wildlife CRWA Colorado Rural Water Association CSFS Colorado State Forest Service CWPP Community Wildfire Protection Plan DRMS Division of Reclamation, Mining and Safety DWIA Drinking Water Importance Area DWRI Drinking Water Risk Index ERP Emergency Response Plan FHL Farmers Highline Canal GIS Geographic Information System GWPC Groundwater Protection Council HFRA Healthy Forests Restoration Act HUC Hydrologic Unit Code MGD Million Gallons Per Day NRCS Natural Resources Conservation Service PSOC Potential Source of Contamination SLC Standley Lake Cities SWAA Source Water Assessment Area SWAP Source Water Assessment and Protection SWPA Source Water Protection Area SWPP Source Water Protection Plan TN Total Nitrogen TOT Time of Travel TP Total Phosphorus USEPA United States Environmental Protection Agency USGS United States Geological Survey WTP Water Treatment Plant WUI Wildland Urban Interface ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 6 EXECUTIVE SUMMARY There is a growing effort in Colorado to protect community drinking water sources from potential contamination. Many communities are taking a proactive approach to preventing the pollution of their drinking water sources by developing a source water protection plan (SWPP). A SWPP identifies a source water protection area (SWPA), lists potential contaminant sources, and outlines best management practices to reduce risks to the water source. Implementation of a source water protection plan provides an additional layer of protection at the local level beyond drinking water regulations. City of Arvada values a clean, high quality drinking water supply and decided to work collaboratively with area stakeholders to develop a SWPP. The source water protection planning effort consisted of public planning meetings with stakeholders including landowners, public water systems, local and state governments, and agency representatives during the months of June 2019 to March 2020, at both the Ralston Water Treatment Plant and the Whisper Creek Community Police Station in Arvada. Colorado Rural Water Association was instrumental in this effort by providing technical assistance in the development of this Source Water Protection Plan. City of Arvada obtains its drinking water from two surface water sources at Ralston and Arvada Reservoirs, respectively. Ralston Reservoir stores water from Ralston Creek and South Boulder Creek via the South Boulder Diversion Canal. Arvada Reservoir stores water from Ralston Creek, South Boulder Creek via the South Boulder Diversion Canal, and Clear Creek. Clear Creek water is delivered to Arvada Reservoir via the Church Ditch, Farmers Highline Canal, and Croke Canal. The Source Water Protection Areas for Ralston Reservoir are: Zone 1 • a 100-foot buffer surrounding Ralston Reservoir • a 100-foot buffer from the centerline of Ralston Creek extending west to the Schwartzwalder Mine maintained by Colorado Legacy Land Mine • a 100-foot buffer surrounding the South Boulder Diversion Canal Zone 2 • the Gross Reservoir sub-watershed to the north (HUC 12 101900050504) and the Middle Ralston Creek sub-watershed to the south (HUC 12 101900040304) The Source Water Protection Areas for Arvada Reservoir are: Zone 1 • a 100-foot buffer surrounding Arvada Reservoir • a 100-foot buffer from the centerline of Ralston Creek extending west to Ralston Reservoir and east to Indiana Street • a 100-foot buffer surrounding Church Ditch, Farmers Highline Canal, and Croke Canal Zone 2 • a two square mile area bordering Arvada Reservoir to the west, West 72nd Avenue to the north, West 64th Avenue to the south, and Indiana Street to the east This SWPA is the area that City of Arvada has chosen to focus its source water protection measures to reduce source water susceptibility to contamination. The Steering Committee conducted an inventory of potential contaminant sources and identified other issues of concern within the SWPA. ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 7 The Steering Committee developed several best management practices (BMPs) to reduce the risks from the potential contaminant sources and other issues of concern. The BMPs are centered on the themes of building partnerships with community members, businesses, and local decision makers; raising awareness of the value of protecting community drinking water supplies; and empowering local communities to become stewards of their drinking water supplies by taking actions to protect their water sources. The following list highlights the highest priority potential contaminant sources and/or issues of concern and their associated BMP recommendations: Nitrogen and Phosphorus in Arvada Reservoir 1. Purchase an upgraded boat to conduct nutrient water quality monitoring. 2. Work with appropriate parties to address water quality issues related to FHL flow through Golf Course settling ponds. 3. Create wetland habitat where golf course settling pond now exist. 4. Create a floating plant island at the Church Ditch settling pond to absorb nutrients. 5. Conduct shoreline area enhancements adjacent to the Church Ditch and other golf course ponds. 6. Work with West Woods Golf Club to develop a Water Quality Monitoring and Mitigation Plan to complement their Audubon Certification. Aquatic Nuisance Species in Arvada Reservoir and the Canal System 1. Continue and enhance the Zebra and Quagga mussels monitoring program currently in place. • Install a Zebra and Quagga mussel boat decontamination station. 2. Conduct education and outreach to recreationists who use boats on the Reservoir. 3. Conduct a comprehensive investigation of Eurasian watermilfoil in the Croke and FHL Canals and Arvada Reservoir. 4. Partner with Standley Lake Cities and canal ditch riders to conduct aquatic nuisance species removal in the canal zone. 5. Provide area businesses that sell fishing licenses with Colorado Parks and Wildlife (CPW) educational material to display and distribute to customers to inform them about strategies to prevent the spread of aquatic nuisance species. 6. Investigate future treatment and mitigation options. Schwartzwalder Mine Above Ralston Reservoir 1. Continue partnership with Denver Water, Colorado Legacy Land, and DRMS to monitor activities at the site including: • Water quality monitoring and data sharing. • Attendance at relevant meetings concerning mine reclamation activities. • Receive updates on all reclamation projects. • Active engagement with CLL permit amendments and technical publications. • Encourage CLL to continue to develop more robust hydraulic models, to evaluate and monitor contamination, and support perpetual treatment and management of the mine. Wildland Fire 1. Provide a copy of the final Source Water Protection Plan to agencies involved in wildland fire fighting and land management decision making during the planning of pre- and post-wildfire mitigation strategies. ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 8 2. Conduct wildfire mitigation activities near the city’s urban water infrastructure, especially the most pertinent, least expensive, and least time-consuming options. 3. Explore opportunities for local partnerships to fund projects within shared watersheds. The Steering Committee recognizes that the usefulness of this SWPP lies in its implementation and will begin to execute these best management practices upon completion of this Plan. This Plan is a living document that is meant to be updated to address any changes that will inevitably come. The Steering Committee will review this Plan at a frequency of once every five years or if circumstances change resulting in the development of new water sources and SWPAs, or if new risks are identified. ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 9 INTRODUCTION Source water protection is a proactive approach to preventing the pollution of lakes, rivers, streams, and groundwater that serve as sources of drinking water. For generations water quality was taken for granted, and still today many people assume that their water is naturally protected. However, as water moves through and over the ground, contaminants may be picked up and carried to a drinking water supply. While a single catastrophic event may temporarily or permanently damage a drinking water source, the cumulative impact of minor contaminant releases over time can also result in the degradation of a drinking water source. Contamination can occur via discrete (point source) and dispersed (nonpoint source) sources. A discrete source contaminant originates from a single point, while a dispersed source contaminant originates from diffuse sources over a broader area. According to the US Environmental Protection Agency (USEPA), nonpoint source pollution is the leading cause of water quality degradation (GWPC, 2008). Figure 1: Schematic drawing of the potential source of contamination to surface and groundwater Source: Groundwater Atlas of Colorado City of Arvada recognizes the potential for contamination of their drinking water sources and realizes that the development of this SWPP is the first step in protecting this valuable resource. Proactive planning is essential to protect the long-term integrity of the drinking water supply and to limit costs and liabilities. This SWPP demonstrates City of Arvada’s commitment to reducing risks to their drinking water supply. ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 10 Figure 2: Location of City of Arvada Within Colorado Source: CRWA Figure 3: Location of City of Arvada in Denver Metro Region Source: CRWA ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 11 Purpose of the Source Water Protection Plan The SWPP is a tool for City of Arvada to ensure clean and high-quality drinking water sources for current and future generations. This SWPP is designed to: • Create an awareness of the community’s drinking water sources and the potential risks to surface water and/or groundwater quality within the watershed. • Encourage education and voluntary solutions to alleviate pollution risks. • Promote management practices to protect and enhance the drinking water supply. • Provide for a comprehensive action plan in case of an emergency that threatens or disrupts the community water supply. Developing and implementing source water protection measures at the local level (i.e. county and municipal) will complement existing regulatory protection measures implemented at the state and federal governmental levels by filling protection gaps that can only be addressed at this level. Background of Colorado’s SWAP Program Source water assessment and protection came into existence in 1996 as a result of Congressional reauthorization and amendment of the Safe Drinking Water Act. These amendments required each state to develop a source water assessment and protection (SWAP) program. The Water Quality Control Division, an agency of the Colorado Department of Public Health and Environment (CDPHE), assumed the responsibility of developing Colorado’s SWAP program and integrated it with the Colorado Wellhead Protection Program. Colorado’s SWAP program is an iterative, two-phased process designed to assist public water systems in preventing potential contamination of their untreated drinking water supplies. The two phases include the Assessment Phase and the Protection Phase as depicted in the upper and lower portions of Figure 4. Figure 4: Source Water Assessment and Protection Phases Source: CDPHE ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 12 Source Water Assessment Phase The Assessment Phase for all public water systems in Colorado was completed in 2004 and then revised in 2007. They consisted of four primary elements: 1. Delineating the source water assessment area for each of the drinking water sources. 2. Conducting a contaminant source inventory to identify potential sources of contamination within each of the source water assessment areas. 3. Conducting a susceptibility analysis to determine the potential susceptibility of each public drinking water source to the different sources of contamination. 4. Reporting the results of the source water assessment to the public water systems and the general public. A Source Water Assessment Report (Appendix which outlines the results of the Assessment Phase, was initially provided to each public water system in Colorado in 2004 and then a revised report was posted on CDPHE website in 2007. Source Water Protection Phase The Protection Phase is a non-regulatory, ongoing process in which all public water systems have been encouraged to voluntarily employ preventive measures to protect their water supply from the potential sources of contamination to which it may be most susceptible. The Protection Phase can be used to take action to avoid unnecessary treatment or replacement costs associated with potential contamination of the untreated water supply. Source water protection begins when local decision makers use the source water assessment results and other pertinent information as a starting point to develop a protection plan. As depicted in the lower portion of Figure 4, the source water protection phase for all public water systems consists of four primary elements: 1. Involving local stakeholders in the planning process. 2. Developing a comprehensive protection plan for all of their drinking water sources. 3. Implementing the protection plan on a continuous basis to reduce the risk of potential contamination of the drinking water sources. 4. Monitoring the effectiveness of the protection plan and updating it accordingly as future assessment results indicate. The water system and the community recognize that the Safe Drinking Water Act grants no statutory authority to the CDPHE or to any other state or federal agency to force the adoption or implementation of source water protection measures. This authority rests solely with local communities and local governments. The source water protection phase is an ongoing process as indicated in Figure 4. The evolution of the SWAP program is to incorporate any new assessment information provided by the public water supply systems and update the protection plan accordingly. ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 13 SOURCE WATER SETTING Location and Description City of Arvada is a Home Rule Municipality in Jefferson and Adams Counties, Colorado. In 2016 the estimated population was 117,453, ranking Arvada as the seventh most populous municipality in Colorado. The Olde Town Arvada historic district is 7 miles (11 km) northwest of the Colorado State Capitol in Denver. The first documented discovery of gold in the Rocky Mountain region occurred on June 22, 1850, when Lewis Ralston, a Georgia prospector headed for the California gold fields, dipped his sluice pan into a small stream near its mouth at Clear Creek. Ralston found about 1/4 ounce (6 g) of gold, then worth about five dollars. Ralston's companions named the stream Ralston's Creek in his honor, but they all left the next morning, drawn by the lure of California gold. During the Pike's Peak Gold Rush in 1858, Ralston brought another group of prospectors back to the site of his first discovery. The placer gold in the area soon played out, but hard rock deposits of gold were found in the mountains to the west. Some of the miners abandoned their search for gold and returned to farm the rich bottom land along Ralston Creek and Clear Creek. They found an eager market for their crops among other gold seekers. The Territory of Colorado was formed on February 28, 1861, and the farms in the valley expanded to feed the growing population of the region. In 1870, the Colorado Central Railroad laid tracks through the area on its route from Golden to link up with the Kansas Pacific Railroad and the Denver Pacific Railroad at Jersey Junction, 3 miles (5 km) north of Denver. On December 1, 1870, Benjamin F. Wadsworth and Louis A. Reno platted the Ralston Point townsite along the railroad. To avoid confusion with other communities along Ralston Creek, Ralston Point was soon renamed Arvada in honor of Hiram Arvada Haskin, brother-in-law of settler Mary Wadsworth. Her husband, Benjamin Wadsworth, became the first postmaster of Arvada. Colorado was granted statehood on August 1, 1876, and the Town of Arvada was formally incorporated on August 14, 1904. A vibrant agricultural community, Arvada claimed the title "Celery Capital of the World." Arvada grew rapidly during the latter half of the 20th century as a suburb of nearby Denver, the state capital. Arvada became a Statutory City on October 31, 1951, and a Home Rule Municipality on July 23, 1963. By the end of the millennium, the population of Arvada exceeded 100,000. Arvada is located primarily in northeastern Jefferson County at 39°49′12″N 105°6′40″W (39.819962, - 105.110975) and a very small portion of Adams County. According to the United States Census Bureau, the city has a total area of 32.8 square miles (85 km2) (Wikipedia). ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 14 Figure 5: Land ownership within the Clear Creek watershed Source: NRCS Rapid Assessment Figure 6: Elevation within the Clear Creek watershed Source: NRCS Rapid Assessment Figure 7: Precipitation within the Clear Creek watershed Source: NRCS Rapid Assessment City of Arvada City of Arvada City of Arvada ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 15 Hydrologic Setting Arvada’s drinking water comes from two surface water sources: Denver Water’s Moffat System and Clear Creek. Denver Water’s Moffat System is City of Arvada’s year-round source, supplying approximately 75% of the drinking water supply. The majority of this mountain water is snowmelt and is collected from the upper sections of the Fraser and Williams Fork Rivers and transported to South Boulder Creek through the Moffat Tunnel. Water is diverted of Gross Reservoir through the South Boulder Diversion Canal to Ralston Reservoir. The remainder of the city’s water supply is diverted from Clear Creek through a series of canals to the Arvada Reservoir until needed for the spring/summer months when water demands peak (City of Arvada Water Quality Report, 2019). Figure 8: Big Picture Hydrology of City of Arvada’s Water Sources Source: City of Arvada 2019 Water Quality Report Figure not included in public version of document Figure 9: Local Hydrology of City of Arvada’s Water Sources Source: CRWA ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 16 DRINKING WATER SUPPLY OPERATIONS Water Supply and Infrastructure All of the city’s water is processed through one of two Water Treatment Plants (WTPs) for purification and disinfection before it is conveyed to the customer. Extensive monitoring of the process takes place to ensure high-quality drinking water. There are more than 632 miles of drinking water distribution pipes and 10 water storage tanks that transport approximately 6 billion gallons of drinking water every year to the city’s residents and businesses (City of Arvada Water Quality Report, 2019). Table 1: Surface Water Supply Information Surface Water Source Water System Facility Number Water System Facility Name Plant Constructed Date Ralston Reservoir CO 0130001-001 Ralston WTP 1960 Arvada Reservoir CO 0130001-002 Arvada WTP 1984 Ralston Reservoir Water System Ralston Reservoir is owned by Denver Water and represents 75% of City of Arvada’s drinking water supply. On average, 4% of that water comes from Ralston Creek, 15% from South Boulder Creek, and 81% is from the west slope. Ralston Creek water is also diverted above the reservoir via pipeline and into Upper Long Lake. Upper and Lower Long Lakes are used primarily to irrigate the Jefferson County North Athletic Complex ballfields and the lakes also store water for non-potable uses surrounding Denver Water property. The Ralston Treatment Plant operates year-round. Figure 10 - 12: Ralston Reservoir Source: CRWA ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 17 Figure not included in public version of document Figures 13 - 16: South Boulder Diversion Canal, clockwise from upper left - at Eldorado Springs, west of Rocky Flats, at CO Highway 93, entering Ralston Reservoir Source: CRWA Figure 17: Ralston Creek Diversion Location Source: CRWA ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 18 Figures 18 & 19: Ralston Creek Diversion Structure Source: CRWA Figure 20: Ralston Reservoir and Upper and Lower Long Lakes Source: CRWA Arvada Reservoir Water System Arvada Reservoir is the City of Arvada’s secondary water source supplying 25% of the total water supply. 35% of that water comes from Ralston Creek (via Ralston Reservoir) and 65% of that water supply comes from Clear Creek via Church Ditch, Farmers Highline Canal (FHL), and Croke Canal. Church Ditch begins at a headgate in Clear Creek west of Golden, CO. The ditch travels northwest 26 miles through Jefferson County until it ends at the intersection of 100th Avenue and Simms Street. Church Ditch is a carrier ditch operated by the Church Ditch Water Authority and can flow April through November (Church Ditch Water Authority). Arvada takes water from Church Ditch which then flows through two settling ponds on the West Woods golf course into Church Pump Station where it is pumped into Arvada Reservoir (see Figure 27). Upper and Lower Long Lakes Ralston Creek Diversion Ralston Reservoir South Boulder Diversion Canal ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 19 The Farmer’s Highline Canal diversion begins at the Coors Brewery plant on the western edge of the property and runs north to Standley Lake. FHL water is diverted from Clear Creek in the summer and holds one of Clear Creek’s most senior irrigation-season water rights. Arvada takes water from Farmer’s Highline Canal at a diversion located where the canal crosses McIntyre Street at West Woods golf course. The water flows through a golf course pond to Croke Pump Station where it is then pumped into Arvada Reservoir (Figure 32). The Croke Canal diversion is located on the eastern edge of the Coors Brewery plant. From there the Canal travels approximately 11 miles north to Standley Lake. Croke Canal has year-round water rights which Arvada diverts during the summer months at the Croke Pump Station where it is then pumped into Arvada Reservoir (Figure 35). The Arvada Water Treatment Plant operates seasonally and as needed. Figure 21: Church Ditch Diversion off Clear Creek Source: CRWA ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 20 Figure 22 - 24: Farmers Highline Canal Diversion off of Clear Creek Source: CRWA * Croke Canal and Church Ditch Diversions off of Clear Creek are approximately 1.5 miles east and west of this location respectively Figure 25: Croke Canal Headgate at Coors Plant Source: CRWA ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 21 Church Ditch Diversion and Pump Station at West Woods Golf Club • Two settling ponds are located at the western end of the golf course. • Water is sent through the Pump Station to Arvada Reservoir. Figure 26: Church Ditch Diversion and Pump Station Source: CRWA Figure 27 - 30: Church Ditch Diversion, clockwise from upper left – Diversion Structures, Pump Station & Settling Ponds Source: CRWA ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 22 Farmers Highline Canal Diversion at West Woods Golf Club • In the summer water is always diverted from Clear Creek into the FHL, it has one of the most senior irrigation-season water rights on Clear Creek. • Water is diverted from FHL to a golf course pond which is then sent to the Croke Pump Station where it may or may not be mixed with Croke Canal water, and from there pumped into Arvada Reservoir. Figure 31: FHL Headgate at Golf Course Source: CRWA Figures 32 & 33: FHL diversion and Holding pond Source: CRWA Croke Canal Diversion at West Woods Golf Club • Water is pulled from Croke Canal at the Croke Pump Station. • Diverted water flows directly into Croke Pump Station. • Farmers Highline Canal water enters Croke Pump Station here as well. ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 23 Figure 34: Croke Canal Diversion and Pump Station Location Source: CRWA Figures 35 & 36: Croke Canal Diversion and Pump Station Source: CRWA ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 24 Figure not included in public version of document Figure 37: Arvada Reservoir and Surrounding Infrastructure Source: CRWA Figures 38 - 41: Arvada Reservoir, clockwise from upper left – west inlet facing west and east, Reservoir settling pond Source: CRWA FHL Diversion ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 25 Figure not included in public version of document Figure 42: City of Arvada Water Infrastructure Big Picture Source: CRWA Figure 43: Water System Diagram Source: City of Arvada ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 26 Water Supply Demand Analysis The City of Arvada serves an estimated 38,800 connections and approximately 145,000 residents and other users in the service area annually. The water system currently has the capacity to produce 52 million gallons of water per day (MGD). Current (2019) estimates by the water system indicate that the average daily demand is approximately 16.5 MGD, and that the average peak daily demand is approximately 38.9 MGD. Using these estimates, the water system has a surplus average daily demand capacity of 35.5 MGD and a surplus average peak daily demand capacity of 13.1 MGD. The ability of City of Arvada to meet these demands if a water source becomes disabled is also affected by the amount of treated water the water system has in storage. City of Arvada recognizes that potential contamination of its surface water sources could result in having to perform additional treatment and/or abandon the water source and seek alternative solutions if treatment proves to be impossible. The city estimates that it would cost a significant amount of money to replace one of its water sources. The potential financial and water supply risks related to the long- term loss of one or more of the community’s water sources are a concern to the Steering Committee. As a result, the Steering Committee believes the development and implementation of a source water protection plan for City of Arvada can help to reduce the risks posed by potential contamination of its water sources. ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 27 SOURCE WATER PROTECTION PLAN DEVELOPMENT The Colorado Rural Water Association’s (CRWA) Source Water Protection Specialist, Paul Hempel, helped facilitate the source water protection planning process. The goal of CRWA’s Source Water Protection Program is to assist public water systems in minimizing or eliminating potential risks to drinking water supplies through the development and implementation of Source Water Protection Plans. The source water protection planning effort consisted of a series of public planning meetings and individual meetings. Information discussed at the meetings helped City of Arvada develop an understanding of the issues affecting source water protection for the community. The Steering Committee then made recommendations for best management practices to be incorporated into the Source Water Protection Plan. In addition to the planning meetings, data and other information pertaining to Source Water Protection Area was gathered via public documents, internet research, phone calls, emails, and field trips to the protection area. A summary of the meetings is represented below. Table 2: Planning Meetings Date Purpose of Meeting June 13, 2019 First Planning Meeting - Presentation on the process of developing a Source Water Protection Plan for City of Arvada. Review of the State’s Source Water Assessment for City of Arvada. August 12, 2019 PSOC Discussion – Meeting to discuss potential sources of contamination to both Ralston and Arvada Reservoirs. August 22, 2019 First Planning Workshop – Special presentations by Denver Water, Division of Reclamation, Mining and Safety (DRMS) and Colorado Legacy Land about operations at Ralston Reservoir and the former Schwartzwalder Mine. October 15, 2019 Second Planning Workshop – Presentation on status of oil and gas development in the area and Arvada Reservoir PSOC discussion. December 3, 2019 Third Planning Workshop – Continue discussions of PSOCs to Arvada Reservoir. Assess risk levels of all PSOCs. January 29, 2020 Fourth Planning Workshop –Determine source water protection areas and select Best Management Practices. March 10, 2020 Fifth Planning Workshop – Review draft SWPP. Stakeholder Participation in the Planning Process Local stakeholder participation is vitally important to the overall success of Colorado’s SWAP program. Source water protection was founded on the concept that informed citizens, equipped with fundamental knowledge about their drinking water source and the threats to it, will be the most effective advocates for protecting this valuable resource. Local support and acceptance of the Source Water Protection Plan is more likely when local stakeholders have actively participated in its development. ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 28 City of Arvada’s source water protection planning process attracted interest and participation from 25 stakeholders including local citizens and landowners, private businesses, water operators, local and state governments, and agency representatives. During the months of June 2019 through March 2020, seven planning meetings were held at the city’s Ralston Water Treatment Plant and the Whisper Creek Community Police Station to encourage local stakeholder participation in the planning process. A Steering Committee to help develop the source water protection plan was formed from the stakeholder group. The Steering Committee’s role in the source water protection planning process was to advise City of Arvada in the identification and prioritization of potential contaminant sources as well as management approaches that can be voluntarily implemented to reduce the risks of potential contamination of the untreated source water. All Steering Committee members attended at least two meetings and contributed to planning efforts from their areas of experience and expertise. Their representation provided diversity and led to a thorough SWPP. City of Arvada and CRWA are very appreciative of the participation and expert input from the participants listed in Table 3. Table 3: Stakeholders and Steering Committee Members Stakeholder Affiliation Steering Committee Member Kindra Greentree City of Arvada X Josh Gryziec City of Arvada X Tara Kratzer City of Arvada X Evelyn Rhodes City of Arvada X Patrick Miklos City of Arvada Sandra McDonald City of Arvada X Brad Wyant City of Arvada Cody Henry City of Arvada Kaitlin McCann City of Arvada X Dan Pumphrey City of Arvada Keith Bohan City of Arvada Bob Krugmire City of Westminster Kelly Cline City of Westminster X Jim Ford City of Blackhawk Stephanie Crabtree City of Golden X Kerry Major City of Golden Roy Laws Jefferson County Mitch Brown Jefferson County Alison Witheridge Denver Water X Cindy Brady Denver Water ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 29 John Duggan CDPHE Kristen Hughes CDPHE X Tripp Minges CDOT Marc Morton COGCC Michael Cunningham DRMS Jim Harrington Colorado Legacy Land Development and Implementation Grant City of Arvada has been awarded a $5,000 Development and Implementation Grant from the Colorado Department of Public Health and Environment (CDPHE). This funding is available to public water systems and representative stakeholders committed to developing and implementing a source water protection plan. A one-to-one financial match (cash or in-kind) is required. City of Arvada was approved for this grant in May 2019, and it expires on May 29, 2021. City of Arvada intends to use 100 percent of the funds to implement best management practices that are identified in this Plan. Source Water Assessment Report Review City of Arvada has reviewed the 2004 and 2007 Source Water Assessment Reports along with the Steering Committee. These Assessment results were used as a starting point to guide the development of appropriate management approaches to protect the source waters of City of Arvada from potential contamination. A copy of the Source Water Assessment Report for City of Arvada can be obtained by contacting the City of Arvada or by downloading a copy from the CDPHE’s SWAP program website located at: Defining the Source Water Protection Area A source water protection area (SWPA) is the surface and subsurface areas within which contaminants are reasonably likely to reach a water source. The purpose of delineating a SWPA is to determine the recharge area that supplies water to a public water source. Delineation is the process used to identify and map the area around a pumping well that supplies water to the well or spring, or to identify and map the drainage basin that supplies water to a surface water intake. The size and shape of the area depends on the characteristics of the aquifer and the well, or the watershed. The source water assessment area that was delineated as part of City of Arvada’s Source Water Assessment Report provides the basis for understanding where the community’s source water and potential contaminant threats originate, and where the community has chosen to implement its source water protection measures in an attempt to manage the susceptibility of their source water to potential contamination. After carefully reviewing their Source Water Assessment Report and the CDPHE’s delineation of the Source Water Assessment Area (SWAA) for each of City of Arvada’s sources, the Steering Committee chose to modify the boundaries before accepting their SWPA for this SWPP. City of Arvada’s Source Water Protection Areas are defined as: ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 30 Ralston Reservoir Zone 1 • a 100-foot buffer surrounding Ralston Reservoir • a 100-foot buffer from the centerline of Ralston Creek extending west to the Schwartzwalder Mine • a 100-foot buffer surrounding the South Boulder Diversion Canal Zone 2 • the Gross Reservoir sub-watershed to the north (HUC 12 101900050504) and the Middle Ralston Creek sub-watershed to the south (HUC 12 101900040304) Arvada Reservoir Zone 1 • a 100-foot buffer surrounding Arvada Reservoir • a 100-foot buffer from the centerline of Ralston Creek extending west to Ralston Reservoir and east to Indiana Street • a 100-foot buffer surrounding Church Ditch and the Farmers Highline and Croke Canals Zone 2 • a two square mile area bordering Arvada Reservoir to the west, West 72nd Avenue to the north, West 64th Avenue to the south and Indiana Street to the east The Source Water Protection Areas are illustrated in the following maps: ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 31 Figure 44: City of Arvada SWPAs Source: CRWA ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 32 Figure 45: Ralston Reservoir SWPAs Source: CRWA Figure 46: Arvada Reservoir SWPAs Source: CRWA ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 33 Inventory of Potential Contaminant Sources and Other Issues of Concern In 2001–2002, as part of the Source Water Assessment Report, a contaminant source inventory was conducted by the CDPHE to identify selected potential sources of contamination that might be present within the source water assessment areas. Discrete and dispersed contaminant sources were inventoried using selected state and federal regulatory databases, land use/land cover maps, and transportation maps of Colorado. The contaminant inventory was completed by mapping the potential contaminant sources with the aid of Geographic Information System (GIS) software. City of Arvada was asked by CDPHE to review the inventory information, field-verify selected information about existing and new contaminant sources, and provide feedback on the accuracy of the inventory. Through this Source Water Protection Plan, City of Arvada is reporting its findings to the CDPHE. After much consideration, discussion, and input from local stakeholders, City of Arvada and the Steering Committee have developed a more accurate and current inventory of contaminant sources located within the Source Water Protection Area and other issues of concern that may impact City of Arvada’s drinking water sources.1 In addition to the discrete and dispersed contaminant sources identified in the 2007 contaminant source inventory, the Steering Committee has also identified new issues of concern that may impact City of Arvada’s drinking water sources (see Table 4: Potential Sources of Contamination and Issues of Concern Prioritization Table). Upon completion of this contaminant source inventory, City of Arvada has decided to adopt it in place of the original contaminant source inventory provided by the CDPHE. Priority Strategy of Potential Contaminant Sources and Other Issues of Concern After developing a contaminant source inventory and list of issues of concern that is more accurate, complete, and current, City of Arvada prioritized each item to guide the implementation of the best management practices (BMPs) outlined in this Source Water Protection Plan (see Table 5: Source Water Protection Best Management Practices). The prioritization ranking of each potential contaminant source or other issue of concern factored in the following criteria (as described below): the level of risk, the water system control, and the best management practices associated with each item. 1. Risk – The level of risk for each contaminant source is a measure of the water source’s potential exposure to contamination. When prioritizing, a water system may assign a higher priority ranking to a potential contaminant source that has a higher risk level than one of lower risk level. City of Arvada utilized CRWA’s SWAP Risk Assessment Matrix (Figure 47) which calculates the level of risk by estimating the following: • Probability of Impact – The risk to the source waters increases as the relative probability of damage or loss increases. The probability of impact is determined by evaluating the number of contaminant sources, the migration potential or proximity to the water source, and the historical data. The following descriptions provide a 1 The information contained in this Plan is limited to that available from public records and the City of Arvada at the time that the Plan was written. Other potential contaminant sites or threats to the water supply may exist in the Source Water Protection Area that are not identified in this Plan. Furthermore, identification of a site as a “potential contaminant site” should not be interpreted as one that will necessarily cause contamination of the water supply. ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 34 framework to estimate the relative probability that damage or loss would occur within one to ten years: • Certain: >95% probability of impact • Likely: >70% to <95% probability of impact • Possible: >30% to <70% probability of impact • Unlikely: to <30% probability of impact • Rare: probability of impact • Impact to the Public Water System – The risk to the source waters increases as the impact to the water system increases. The impact is determined by evaluating the human health concerns and potential volume of the contaminant source. CDPHE developed information tables to assist with this evaluation (Appendices B-E). The following descriptions provide a framework to estimate the impact to the public water system: • Catastrophic - irreversible damage to the water source(s). This could include the need for new treatment technologies and/or the replacement of existing water source(s). • Major - substantial damage to the water source(s). This could include a loss of use for an extended period of time and/or the need for new treatment technologies. • Significant - moderate damage to the water source(s). This could include a loss of use for an extended period of time and/or the need for increased monitoring and/or maintenance activities. • Minor - minor damage resulting in minimal, recoverable, or localized efforts. This could include temporarily shutting off an intake or well and/or the issuance of a boil order. • Insignificant - damage that may be too small or unimportant to be worth consideration but may need to be observed for worsening conditions. This could include the development of administrative procedures to maintain awareness of changing conditions. Figure 47: CRWA’s SWAP Risk Assessment Matrix Source: CRWA ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 35 2. Control – The level of water system control describes the ability of the water system to take measures to prevent contamination or minimize impact. A potential contaminant source that falls within a water system’s jurisdiction (i.e. direct control), may be of higher priority since they can take direct measures to prevent contamination or minimize the impact. • Direct Control – The water system can take direct measures to prevent or minimize. • Indirect Control – The water system cannot directly control the issue but can work with another person or entity to take measures to prevent or minimize. • No Control – The PSOC or issue of concern is outside the control of the public water system and other entities. 3. Best Management Practices – BMPs are the actions that can be taken within the Source Water Protection Area to help reduce the potential risks of contamination to the community’s source waters. The prioritization of the potential contaminant sources or issues of concern may be affected by the feasibility of implementing the BMPs that the City of Arvada developed. City of Arvada and Steering Committee ranked the potential contaminant source inventory and issues of concern in the following way: Table 4: Potential Contaminant Sources and Issues of Concern Prioritization Table Potential Contaminant Source or Issue of Concern Proximity (SWPA Zone) Probability of Impact (Rare, Unlikely, Possible, Likely, Certain) Impact to Water System (Insignificant, Minor, Significant, Major, Catastrophic) Risk (Very Low, Low, Moderate, High, Very High) Control (Direct, Indirect, No) Priority Ranking Ralston Reservoir Schwartzwalder Uranium Mine 1 Likely Minor Moderate Indirect Med Other Mining Operations 2 Unlikely Minor Low Indirect Low Wildland Fire 1 & 2 Possible Significant Moderate Indirect High Breecher Lake Headwaters 2 Rare Insignificant Very Low Indirect Low Backcountry Recreation 2 Unlikely Minor Low No Low Flooding 1 Possible Significant Moderate Indirect High South Boulder Diversion Canal 1 Rare Insignificant Very Low Indirect Low Security 1 Rare Significant Very Low No Low Arvada Reservoir Nutrients: Nitrogen and Phosphorus 1 Certain Significant High Direct/ Indirect High ANS: Mussels 1 Unlikely Catastrophic Moderate Direct High ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 36 ANS: Watermilfoil 1 Certain Minor Moderate Direct/ Indirect Med Highway 93 1 Rare Insignificant Very Low No Low Sand and Gravel Ops NA Rare Insignificant Very Low Indirect Low Sediment Loading: Ralston Reservoir Draining 1 Possible Insignificant Low Indirect Med Oil and Gas Development NA Rare Insignificant Very Low No Low Recreation 1 Certain Minor Moderate Direct Med Ralston Reservoir Flooding into Arvada Reservoir 1 Possible Significant Moderate Indirect High Chlorides in the Canal System 1 Certain Insignificant Low Direct/ Indirect Med Jefferson County Parkway NA TBD TBD TBD No TBD Security 1 & 2 Possible Minor Moderate Direct Med ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 37 DISCUSSION OF POTENTIAL CONTAMINANT SOURCES AND ISSUES OF CONCERN The following section provides a brief description of potential contaminant sources and issues of concern that have been identified in this plan, describes the way in which they threaten the water source(s), and outlines best management practices. 1. Nutrients: Nitrogen and Phosphorus in Arvada Reservoir Just as applying fertilizer to gardens and farm fields helps crops grow, nutrients entering lakes and rivers feed the growth of algae, bacteria, and other tiny organisms. Water bodies require some nutrients to be healthy, but too much can be harmful. When lakes receive an overabundance of nutrients, they can become polluted by excessive amounts of algae. Die-off and decomposition of algae blooms can reduce dissolved oxygen and suffocate fish and other aquatic life. Some forms of algae (cyanobacteria) may produce toxins that can be harmful if ingested by humans and animals. Phosphorus and nitrogen are the primary nutrients that in excessive amounts pollute our lakes, streams, and wetlands. Nitrogen is essential to the production of plant and animal tissue. It is used primarily by plants and animals to protein. Nitrogen enters the ecosystem in several chemical forms and also occurs in other dissolved or particulate forms, such as tissues of living and dead organisms. Nitrate, a compound containing nitrogen, can exist in the atmosphere or as a dissolved gas in water, and at elevated levels can have harmful effects on humans and animals. Nitrates in water can cause severe illness in infants and domestic animals. Common sources of excess nitrate reaching lakes and streams include septic systems, animal feed lots, agricultural fertilizers, manure, industrial waste waters, sanitary landfills, and garbage dumps. Phosphorus is a vital nutrient for converting sunlight into usable energy, and essential to cellular growth and reproduction. It is one of the 20 most abundant elements in the solar system, and the 11th most abundant in the earth’s crust. Under natural conditions phosphorus is typically scarce in water. In the late 1960s scientists discovered phosphorus contributed by human activity to be a major cause of excessive algae growth and degraded lake water quality. Phosphorus occurs in dissolved organic and inorganic forms or attached to sediment particles. Phosphates, the inorganic form, are preferred for plant growth, but other forms can be used when phosphates are unavailable. Phosphorus builds up in the sediments of a lake. When it remains in the sediments it is generally not available for use by algae; however, various chemical and biological processes can allow sediment phosphorus to be released back into the water. For example, bottom-feeding rough fish such as carp can stir up bottom sediments, releasing phosphorus back into the water. Poor water quality in lakes can have many unpleasant consequences. Rough fish – such as carp and bullhead – populations increase at the expense of game fish populations. Severe nuisance algal blooms yield unpleasant odor and appearance that reduce the aesthetic appeal of lakes. This may result in declines in fishing and swimming and hurt tourism. As algae die, the decomposition process consumes oxygen. Without enough dissolved oxygen in the water, fish and other organisms may suffer and die because they can't “breathe.” This can occur locally or much farther leading to degraded estuaries, lakes and reservoirs (Minnesota Pollution Control Agency). High nutrient concentrations and algal blooms are a major problem in Arvada Reservoir and taste and odor issues exist. Because of these issues and during the development of this SWPP, City of Arvada ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 38 conducted a water quality study of Total Nitrogen (TN) and Total Phosphorus (TP) in Croke and FHL Canals and Church Ditch, the suspected sources of elevated nutrient concentrations to the Reservoir. Figure 48: City of Arvada golf course area nutrient sampling locations Source: City of Arvada The first suspected source evaluated was water from Croke Canal in an area adjacent to the West Woods Golf Club. Lying on the northeastern fringe of the course, the Croke pump station takes water from both Croke Canal and FHL and pumps it into Arvada Reservoir via two settling basins. Figure not included in public version of document Figure 49: Croke Canal diversion, Pump Station and sampling location Source: City of Arvada ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 39 Figure 50: Croke Diversion sampling location at Arvada Reservoir Source: City of Arvada Major findings from samples taken at this site include: • TN concentrations stayed roughly the same or decreased after settling pond contact earlier in the summer but increased significantly from mid-summer into the fall. • TP concentrations also stayed roughly the same or decreased after settling pond contact earlier in the summer and increased from mid-summer into the fall. • 8/8/2019 sampling event – TN and TP increased to highest post-settling levels. Figures 51 and 52: Croke Canal Total Nitrogen and Total Phosphorus concentrations Source: City of Arvada The second suspected source evaluated was water from FHL in an area adjacent to the south side of the golf course. The FHL diversion there directs water via underground pipe to a pond that is located in a depression on the golf course. The pond catches nutrient runoff from the course. Water from the pond is then sent to the Croke pump station where it may or may not be mixed with Croke Canal water. From there the water is pumped to Arvada Reservoir. ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 40 Figure not included in public version of document Figure 53: FHL Diversion and sampling locations Source: City of Arvada Major findings from samples taken at this site include: • TN increased after contact with the pond. • TP increased after contact with the pond. Figures 54 and 55: Farmer’s Highline Total Nitrogen and Total Phosphorus concentrations Source: City of Arvada The third suspected source evaluated was water from Church Ditch in an area adjacent to the southwest side of the golf course. Directly east of Arvada Reservoir, the Church diversion located there directs water to two settling ponds and the Church pump station. High nutrient concentrations have been found in the settling ponds where geese are present including the larger pond close to the pump station which lies adjacent to a golf course fairway. Water from the pump station is fed to an inlet at Arvada Reservoir via an underground conduit where major concentrations of nutrients have also been detected. ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 41 Figure not included in public version of document Figure 56: Church Diversion and sampling location Source: City of Arvada Figure 57: Church Conduit Inlet and sampling location Source: City of Arvada Major findings from samples taken at this site include: • TN increased after settling pond contact, at times significantly. • TP increased after settling pond contact throughout most of the summer, and stayed the same or decreased into the fall. • 7/22/2019 sampling event – TN and TP increased to the highest post-settling levels – concentrations doubled after settling pond contact. Sampling Location ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 42 Figures 58 and 59: Church Diversion Total Nitrogen and Total Phosphorus concentrations Source: City of Arvada City of Arvada recognizes the impact nutrients have on its drinking water supply and is proposing the following BMPs to help alleviate the problem: Nitrogen and Phosphorus Best Management Practices Recommendations: 1. Purchase an upgraded boat to conduct nutrient water quality monitoring on the Reservoir. 2. Work with appropriate parties to address water quality issues related to FHL flow through Golf Course settling ponds. 3. Create wetland habitat where golf course settling pond now exist. 4. Create a floating plant island at the Church Ditch settling pond to absorb nutrients. 5. Conduct shoreline area enhancements adjacent to the Church Ditch and other golf course ponds. 6. Work with West Woods Golf Club to develop a Water Quality Monitoring and Mitigation Plan to complement their Audubon Certification. 2. Aquatic Nuisance Species Zebra and Quagga Mussels The introduction and spread of the invasive Aquatic Nuisance Species (ANS) Zebra mussel (Dreissena polymorpha) and Quagga mussel (Dreissena rostriformis burgensis) into the waters of Colorado is a concern for drinking water suppliers. The Zebra and Quagga mussels are invasive non-native freshwater bivalve mollusks. They can be differentiated by morphological differences of their shell. The Zebra mussel is more triangular in shape, usually have a striped pattern on their shells and average one inch in length. The Quagga mussel has a rounded carina, larger than the Zebra mussel and paler toward the hinge. Both species of mussels were originally native to the lakes of southeast Russia and were accidentally introduced into other countries from ocean-going ships. The mussels were first discovered in the United States in the Great Lakes in 1988 and spread to a large number of waterways throughout the country. Zebra and Quagga mussels likely made their way to the Western USA on trailered watercraft. The first discovery west of the 100th meridian was in Lake Mead in 2007. Given their ability to attach to hard surfaces and survive out of water for up to 30 days, many infestations have occurred by adult mussels hitching rides on watercraft. Both species of mussels are prolific breeders, thus contributing to their spread and abundance. A fully mature female mussel is capable of producing up to one million eggs per season. Their larvae are microscopic. These invasive mussels smother other aquatic organisms and compete with native species ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 43 for food and habitat. Their massive colonies can clog water intake structures, such as pipes and screens, therefore reducing pumping capabilities for power and water treatment plants, costing industries, companies, and communities. Recreation-based industries and activities have also been impacted; docks, breakwalls, buoys, boats, and beaches have all been heavily colonized (USGS, 2009). At this time, there are no Zebra or Quagga mussels present in any Colorado water bodies. All waters have been de-listed following five years of no detection per Western Regional Panel Standards (Colorado Parks and Wildlife). Figure 60: Zebra and Quagga mussel sightings distribution Source: USGS Eurasian Watermilfoil Eurasian watermilfoil spicatum) is an aquatic plant with feathery underwater foliage that is native to Northern Europe and Asia. Eurasian watermilfoil spreads most commonly by stem fragmentation and runners. The plant roots on the water bottom, but survives and is spread as free- floating plants waiting to take root. Eurasian watermilfoil also spreads by seeds. Eurasian watermilfoil starts spring growth before other native aquatic plants giving it competitive advantage over other species. The plant forms very dense mats of vegetation on the surface of the water that interferes with power generation and irrigation by clogging water intakes. These mats also interfere with recreational activities (e.g. swimming, fishing, skiing, boating, etc.), create mosquito habitat, and reduce native vegetation. Since it was discovered in North America in the 1940s, Eurasian watermilfoil has invaded nearly every U.S. state and at least three Canadian provinces. Milfoil spreads when plant pieces break off and float on water currents. It can cross land to new waters by clinging to sailboats, personal watercraft, ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 44 powerboats, motors, trailers, and fishing gear. Eradicating established infestations is nearly impossible (Sea Grant Minnesota). Eurasian watermilfoil is designated as a “List B” species in the Colorado Noxious Weed Act. It is required to be eradicated; some populations may be contained or suppressed depending on State regulations (Colorado Department of Agriculture). Figure 61: Eurasian watermilfoil Source: Sea Grant Minnesota ANS introduction into Arvada Reservoir is a major concern for the city. Although there have been no sightings of Zebra and Quagga mussels in Arvada Reservoir, the city plans to continue their due diligence to ensure that they stay out. Eurasian watermilfoil on the other hand has been found in the Croke Canal prior to the diversion and is abundant in areas south of the Ralston Creek Crossing. City of Arvada does not have control of the canal zone, and Eurasian watermilfoil will keep coming back. Therefore, the city hopes to control it rather than try to eradicate it. Aquatic Nuisance Species Best Management Practices Recommendations: 1. Continue and enhance the Zebra and Quagga mussels monitoring program currently in place. • Install a Zebra and Quagga mussel boat decontamination station. 2. Conduct education and outreach to recreationists who use boats on Arvada Reservoir. 3. Conduct a comprehensive investigation of Eurasian watermilfoil in the Croke and FHL Canals and Arvada Reservoir. 4. Partner with Standley Lake Cities and canal zone ditch riders to conduct aquatic nuisance species removal in the canal zone. 5. Provide area businesses that sell fishing licenses with CPW educational material to display and distribute to customers to inform them about strategies to prevent the spread of aquatic nuisance species. 6. Investigate future treatment and mitigation options. ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 45 3. Schwartzwalder Mine Above Ralston Reservoir Schwartzwalder Mine is located about seven miles northwest of Golden, adjacent to Ralston Creek about three miles upstream of Ralston Reservoir. A large uranium ore deposit was discovered in 1949 by Fred Schwartzwalder and mining operations began in earnest in 1953. The Cotter Corporation owned and operated the mine from 1965-2018, along with a uranium mill located in Cañon City. The Schwartzwalder was one of the top uranium-producing mines in the US from its discovery until 2000, when uranium prices dropped making the mine unproductive. During the height of the mine’s production the mine was regularly dewatered during excavation practices, causing uranium-laden ground water along with contaminated surface runoff to be discharged into Ralston Creek. To reduce contamination levels, Cotter began water treatment in 1979, and constructed the original on-site water treatment facility in 1987. When the mine production and dewatering operations ceased in 2000, the underground workings of the mine naturally filled with water until 2007, when shallow subsurface flows from the mine resulted in contamination into Ralston Creek. Additionally, mine waste rock containing uranium had been used for building and pond foundations adjacent to Ralston Creek. Due to these contamination concerns, Cotter Corporation was ordered to perform four major remediation steps which included: 1) installing a cutoff wall and pipeline to divert the Creek around the site; 2) dewatering the mine and maintaining it in a dewatered condition to a depth of at least 150 feet below the mine entrance level (“Steve adit level”), so groundwater would not flow toward the Creek but instead be contained in the mine; 3) treating the dewatering water from the mine so that it could be discharged into Ralston Creek safely; and 4) remediating any uranium-containing waste rock that could leach uranium into alluvial soils. Cotter Corporation began work on these actions before the mine was acquired in 2018 by Colorado Legacy Land (CLL), located in Denver. CLL is a partnership of Legacy Land Stewardship, a public benefit corporation, and Alexco Environmental Group, an environmental cleanup company. CLL acquired both the Schwartzwalder Mine and the Cañon City mill, to perform remediation at both sites. The acquisition included 580 acres at the mine area, 2700 acres at the mill site, and management of the sites in compliance with two Radioactive Materials Licenses, a Colorado Division of Reclamation and Mining Safety (DRMS) mining reclamation permit, a CDPS surface water discharge permit, and other items (Legacy Land Stewardship). CLL must comply with all requirements mandated in 2 CCR 407-1 for mine- land reclamation and plans to return the former mining area into wildlife habitat upon completion. Figure 62: Schwartzwalder Mine Source: Colorado Legacy Land, LLC ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 46 Ongoing reclamation activities and environmental operations at the mine site (to date) include: • Closure of the mine openings. • Creation of a Conceptual Site Model to identify hydrologic and geochemical mechanics influencing/controlling the flow and chemistry of water in and around the mine. • Construction of new Water Treatment Plant and demolition and removal of original water treatment facility. • Excavation and removal of contaminated alluvial soils (surface soils) from the site. • Ralston Creek flows are intercepted upstream at a cutoff wall and diverted around the mine site via an 18” diameter HDPE bypass pipeline, then discharged beyond the mine property line, which will continue during the soil remediation process. • Stormwater runoff at the site is being diverted through a lined channel to avoid the North and South Waste Rock Piles (see image above) until soil excavation and removal are complete. • Regular monitoring of groundwater and surface water at multiple locations. • Ongoing study to determine if passive wetland treatment is a viable option in the future for additional uranium removal along the Creek. • Water level in the mine pool is kept below the regulatory depth limit (150 foot below Steve adit level), monitored continuously with a transducer, in order to maintain the hydraulic gradient of the groundwater away from Ralston Creek. • When the mine pool naturally fills to near the regulatory depth limit, water is pumped to the Water Treatment Plant (WTP) where a reverse osmosis (RO) and ion exchange (IX) system removes uranium and other metals and the treated water is discharged to Ralston Creek. The spent RO brine is amended with chemicals to help remove radium and sent back into the mine pool. • The WTP is operated seasonally in the late spring and summer months. • Treatment with RO and IX consistently reduce uranium levels in the WTP discharge to less than 0.03 mg/L (the drinking water MCL). • During the winter months when the WTP is offline, in situ treatments may occur to biologically reduce the uranium levels in the mine pool. • Uranium levels within the mine pool have been reduced from an average of 40 mg/L (pre- 2017), to 10-15 mg/L on average (2018-2021). Schwartzwalder Mine Best Management Practices Recommendations: 1. Continue partnership with Colorado Legacy Land, Denver Water, and DRMS to monitor activities at the site including: • Water quality monitoring and data sharing. • Attendance at relevant meetings concerning mine reclamation activities. • Receive updates on all reclamation projects. • Active engagement with CLL permit amendments and technical publications. • Encourage CLL to continue to develop more robust hydraulic models, to evaluate and monitor contamination, and support perpetual treatment and management of the mine. 4. Wildland Fire Post-wildfire impacts to water treatment are a major concern for water utilities across Colorado. While threats to human health and safety posed by floods, debris flow, and mudslides certainly cause the greatest concern, water quality impacts and their associated risks are nonetheless critical for water utilities and regulatory agencies to address. The potential of a watershed to deliver sediments to surface waters after a wildfire depends on forest and soil conditions, the physical condition of the watersheds, ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 47 and the sequence and magnitude of rain fall on the burned area. In cases of a high-severity fire, normal runoff and erosion processes can be dramatically altered and magnified. Large post-fire sediment fluxes impact drinking water systems in two ways. First and perhaps foremost is the danger that reservoirs, infiltration basins, and treatment works will be filled, damaged, or otherwise disrupted by sediment. Second, high sediment load is likely to increase pre-treatment processing needs and costs for suspended sediment removal (Meixner and Wohlgmuth). Post-fire sediment and debris flow after storm events can also be impactful significantly further In terms of aquatic habitat, large quantities of post-fire sediment can overwhelm the biological habitat available for aquatic organisms such as fish, as well as organisms that depend on water for some life stage, such as amphibians and insects. The chemicals used in fire retardants can also be a source of contamination should they migrate through runoff into drinking water supplies. The degree of contamination is controlled by the size of the burned area, distance to surface water, remaining vegetation cover, terrain, soil erosion potential, and subsequent precipitation and intensity (Walsh Environmental, 2012). Jefferson County Community Wildfire Protection Plan Precipitated by over a decade of increasing wildfire activity, related losses, and spiraling suppression costs, the National Fire Plan was developed by the federal government in 2000. The Healthy Forests Restoration Act (HFRA) of 2003 provides the impetus for wildfire risk assessment and planning at the county and community level and helps implement the core components of the plan. HFRA refers to this level of planning as the Community Wildfire Protection Plan (CWPP). Much of the Colorado Front Range, particularly in Jefferson County, has heavily forested areas and high accumulations of hazardous fuels near metropolitan communities. The conditions to have a catastrophic wildfire in Jefferson County are present and needs to be addressed. According to the Front Range Fuel Treatment Partnership Roundtable’s Findings and Recommendations, Jefferson County has nearly 93,000 acres of forested land that require fire risk mitigation treatment; and 73% of that forested land in need of treatment is privately owned. Therefore, fuels reduction in communities on private land is particularly important. The Jefferson County CWPP is a strategic plan that identifies specific wildland fire risks facing communities and neighborhoods and provides prioritized mitigation recommendations that are designed to reduce those risks. The purpose of the fire behavior analysis and community wildfire hazard rating is to provide a comprehensive, scientifically based assessment of the wildfire hazards and risks within Jefferson County. Once the CWPP is adopted, it is the community’s responsibility to move forward and implement the action items. This may require further planning at the project level, acquisition of funds, and motivating individual homeowners (Jefferson County CWPP). Wildland Urban Interface Colorado is one of the fastest growing states in the Nation, with much of this growth occurring outside urban boundaries. This increase in population across the state will impact counties and communities that are located within the Wildland Urban Interface (WUI). The WUI is described as the area where structures and other human improvements meet and intermingle with undeveloped wildland or vegetative fuels. Population growth within the WUI substantially increases the risk from wildfire. For the ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 48 Clear Creek Watershed project area, it is estimated that 148,714 people or 47.5% percent of the total project area population (312,758) live within the WUI (2020 estimates). Figure 63: Clear Creek Watershed WUI Source: CSFS WUI Risk Index is a rating of the potential impact of a wildfire on people and their homes. WUI reflects housing density (houses per acre) consistent with Federal Register National standards. The location of people living in the wildland-urban interface and rural areas is essential for defining potential wildfire ignitions and impacts to people and homes. To calculate the WUI Risk Index, the WUI housing density data were combined with flame length data and response functions were defined to represent potential impacts. The response functions were defined by a team of experts. By combining flame length with the WUI housing density data, it is possible to determine where the greatest potential impact to homes and people is likely to occur. ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 49 Figure 64: Lower Clear Creek Watershed WUI Risk Source: CSFS Wildfire Risk is defined as the possibility of loss or harm occurring from a wildfire. It is determined from a composite rating obtained by combining the probability of a fire occurring with the individual Values at Risk Layers. The Values at Risk Rating is a key component of Wildfire Risk and is comprised of several inputs focusing on values and assets at risk. This includes Wildland Urban Interface, Forest Assets, Riparian Assets, and Drinking Water Importance Areas (watersheds). Focusing on the highest risk reduces the probability of the occurrence and severity of consequences. Since all areas in Colorado have risk calculated consistently, it allows for comparison and prioritization of areas across the entire state. Figure 65: Lower Clear Creek Watershed Wildfire Risk Source: CSFS ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 50 Drinking Water Importance Areas (DWIA) is the measure of quality and quantity of public surface drinking water categorized by watershed. This layer identifies an index of surface drinking water importance, reflecting a measure of water quality and quantity, characterized by Hydrologic Unit Code 12 (HUC 12) watersheds. The Hydrologic Unit system is a standardized watershed classification system developed by the USGS. Areas that are a source of drinking water are of critical importance and adverse effects from fire are a key concern. Figure 66: Clear Creek Watershed Drinking Water Importance Areas Source: CSFS Drinking Water Risk Index is a measure of the risk to DWIAs based on the potential negative impacts from wildfire. In areas that experience low-severity burns, fire events can serve to eliminate competition, rejuvenate growth, and improve watershed conditions. But in landscapes subjected to high, or even moderate burn severity, the post-fire threats to public safety and natural resources can be extreme. High-severity wildfires remove virtually all forest vegetation – from trees, shrubs and grasses down to discarded needles, decomposed roots and other elements of ground cover or duff that protect forest soils. A severe wildfire also can cause certain types of soil to become hydrophobic by forming a waxy, water-repellent layer that keeps water from penetrating the soil, dramatically amplifying the rate of runoff. Ralston Creek Watershed ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 51 Figure 67: Lower Clear Creek Drinking Water Risk Source: CSFS Moderate and high intensity fires are the biggest concern for the Ralston Creek watershed including post wildland fire mud and debris flow which can carry high volumes of manganese and nutrients. JW Associates has included this watershed within the Clear/Bear Creek Wildfire Watershed Assessment. Link to report and GIS files can be found here: Overall, the wildland fire risk is moderate in the Ralston Creek watershed. Additionally, many mitigation activities in the watershed would be difficult because of the terrain and steep slopes. Arvada can share data with the Natural Resources Conservation Service as needed for their emergency response plan (ERP) for pre- and post-wildfire events in Arvada’s areas of concern. Information can also be included in the Jefferson County ERP for pre- or post-fire flooding/turbidity impacts to the water system. Wildland Fire Best Management Practices Recommendations: 1. Provide a copy of the final SWPP to local Fire Protection Districts, USFS, CSFS, BLM and any other agencies/departments involved in wildfire and land management decision making during the planning of pre-and post-wildfire mitigation strategies. 2. Conduct wildfire mitigation activities near the city’s urban water infrastructure, especially the most pertinent, least expensive, and least time-consuming options. 3. Explore opportunities for local partnerships to fund projects within shared watersheds. 5. Security at Arvada Reservoir The September 11, 2001 attacks on the World Trade Center and the Pentagon have drawn attention to the security of many institutions, facilities, and systems in the United States, including the nation’s water supply and water quality infrastructure. These systems have long been recognized as being potentially vulnerable to terrorist attacks of various types, including physical disruption, bioterrorism/chemical contamination, and cyber-attack. Damage or destruction by a terrorist attack could disrupt the delivery of vital human services in this country, threatening public health and the environment, or possibly causing loss of life. Further, since most water infrastructure is government-owned, it may serve as a symbolic and political target for some. Ralston Reservoir ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 52 A fairly small number of large drinking water utilities located primarily inurban areas (about 15% of the systems) provide water services to more than 75% of the U.S. population. Arguably, these systems represent the greatest targets of opportunity for terrorists who might seek to disrupt water infrastructure systems. Attacks resulting in physical destruction to any of these systems could include disruptionof operating or distribution system components, power or telecommunications systems, electronic control systems, and actual damage to reservoirs and pumping stations. A loss of flowand pressure would cause problems for customers and would hinder firefighting efforts. Further, destruction of a large dam could result in catastrophic flooding and loss of life. Bioterrorism or chemical attacks could deliver widespread contamination with small amounts ofmicrobiological agents or toxic chemicals and could endanger the public health of thousands. Attacks on computer operations can affect an entire infrastructure network and hacking in water utility systems could result in theft or corruption of information, or denial and disruption of service (Congressional Research Service). Overall, security at Arvada Reservoir is effective but could be enhanced. A Ranger is present at all times when the gates are open for recreationists, although there are times when people come into the space between the two outer fences. Occasionally people will have their boats on the Reservoir after closing at sundown. Security at Ralston Reservoir is overseen by Denver Water and is considered substantial and appropriate. Security Best Management Practices Recommendations: 1. Continue to conduct daily site visits at Arvada Reservoir. 2. Enhance the security at the Church Ditch diversion and pump station. • Install additional security cameras. 3. Evaluate effectiveness of fence closures at Arvada Reservoir and determine security needs. 4. Evaluate current security measures/practices and enhance security as needed at all areas of concern (reservoir, pump stations, diversions, etc). 5. Install additional No Trespassing signage where needed. 6. Distribute Emergency Response Notification Cards to Jefferson County Office of Emergency Management. ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 53 SOURCE WATER BEST MANAGEMENT PRACTICES The Steering Committee reviewed and discussed several possible best management practices that could be implemented within the Source Water Protection Area to help reduce the potential risks of contamination to the community’s source water. The Steering Committee established a “common sense” approach in identifying and selecting the most feasible source water management activities to implement locally. The best management practices were obtained from multiple sources including: Environmental Protection Agency, Colorado Department of Public Health and Environment, Natural Resources Conservation Service, and other source water protection plans. The Steering Committee recommends the best management practices listed in the following table be considered for implementation. Table 5: Source Water Protection Best Management Practices Issues City of Arvada Best Management Practices Partners Ralston Reservoir Wildland Fire Risk: Moderate Priority Ranking: High 1. Provide a copy of the final Source Water Protection Plan to local Fire Protection Districts, USFS, CSFS, BLM and any other agencies/departments involved in wildfire and land management decision making during the planning of pre-and post-wildfire mitigation strategies. 2. Conduct wildfire mitigation activities near the Cities urban water infrastructure, especially the most pertinent, least expensive, and least time-consuming options. 3. Explore opportunities for local partnerships to fund projects within shared watersheds. City of Arvada, CSFS, Jefferson CD, NRCS Schwartzwalder Mine Risk: Moderate Priority Ranking: Medium 1. Continue partnership with Denver Water, Colorado Legacy Land, and DRMS to monitor activities at the site including: • Water quality monitoring and data sharing. • Attendance at relevant meetings concerning mine reclamation activities. • Receive updates on all reclamation projects. • Active engagement with CLL permit amendments and technical publications. • Encourage CLL to continue to develop more robust hydraulic models, to evaluate and monitor contamination, and support perpetual treatment and management of the mine. City of Arvada, Denver Water, DRMS, CLL Other Mining Operations Risk: Low Priority Ranking: Low 1. Provide DRMS a copy of the final Source Water Protection Plan. 2. Continue monitoring the water quality of the Ralston Creek watershed: • Develop a water quality monitoring plan to study the effects of abandoned mine reclamation activities in the watershed. • Gather and evaluate water quality monitoring data to help identify where future reclamation activities may be needed. 3. Participate in the review process for mining activity permits at the State and County level and in mine land reclamation activities. City of Arvada ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 54 4. Review upcoming Colorado Geologic Survey study for identification of draining mines. 5. Research mines that may be vulnerable to wildfire and that may drain heavy metals into surface waters during post-wildfire runoff. Flooding Risk: Moderate Priority Ranking: High 1. Explore funding opportunities to upgrade and/or fortify the Ralston Creek diversion structure. 2. Construct levees or other barriers that divert flood waters away from the diversion structures. 3. Utilize current process to notify the public in case of a catastrophic event. 4. Examine the 100-year floodplain and FEMA mapping to determine areas that are susceptible to flood damage. 5. Switch water sources, if possible, to continue providing drinking water to customers. City of Arvada, Denver Water South Boulder Diversion Canal Risk: Very Low Priority Ranking: Low 1. Continue partnership with Denver Water by being informed of activities in the canal area including water quality monitoring data results, land use planning changes, spills or accidents on Highway 93 and the potential future construction of the Jefferson County Parkway. City of Arvada, Denver Water Security Risk: Very Low Priority Ranking: Low 1. Continue partnership with Denver Water by being kept up to date on any contact information changes and notification of any issues that may arise or occur. 2. Distribute Emergency Response Notification Cards (ERNC) to Jefferson County Office of Emergency Management and Denver Water. 3. Install Drinking Water Protection Area signs within the watershed and water treatment and supply facilities. City of Arvada, Denver Water Arvada Reservoir Nitrogen and Phosphorus Risk: High Priority Ranking: High 1. Purchase an upgraded boat to conduct nutrient water quality monitoring on the Reservoir. 2. Work with appropriate parties to address water quality issues related to FHL flow through Golf Course settling ponds. 3. Create wetland habitat where golf course settling pond now exist. 4. Create a floating plant island at the Church Ditch settling pond to absorb nutrients. 5. Conduct shoreline area enhancements adjacent to the Church Ditch and other golf course ponds. 6. Work with West Woods Golf Club to develop a Water Quality Monitoring and Mitigation Plan to complement their Audubon Certification. City of Arvada Aquatic Nuisance Species Mussels Risk: Moderate Priority Ranking: High Watermilfoil Risk: Moderate 1. Continue and enhance the Zebra and Quagga mussels monitoring program currently in place. • Install a Zebra and Quagga mussel boat decontamination station. 2. Conduct education and outreach to recreationists who use boats on the Reservoir. 3. Conduct a comprehensive investigation of Eurasian watermilfoil in the Croke and FHL Canals and Arvada Reservoir. 4. Partner with Standley Lake Cities and canal zone ditch riders to conduct aquatic nuisance species removal in the canal zone. 5. Provide area businesses that sell fishing licenses with CPW educational City of Arvada ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 55 Priority Ranking: Medium material to display and distribute to customers to inform them about strategies to prevent the spread of aquatic nuisance species. 6. Investigate future treatment and mitigation options. Ralston Reservoir Flooding into Arvada Reservoir Risk: Moderate Priority Ranking: High 1. Utilize current process to notify the public in case of a catastrophic event. 2. Examine the 100-year floodplain and FEMA mapping to determine areas that are susceptible to flood damage. 3. Work with Denver Water to divert flood waters. 4. Switch water sources, if possible, to continue to provide drinking water to customers. 5. Continue core sediment sampling to monitor sediment levels. 6. Create a bathometric map to pinpoint areas of high sedimentation. City of Arvada, Denver Water Highway 93 at Ralston Creek Crossing Risk: Very Low Priority Ranking: Low 1. Distribute Emergency Response Notification Cards to Jefferson County OEM, CDOT and Denver Water • Ralston WTP Control Room: [PHONE REDACTED] 2. If necessary, install guardrails at Ralston Creek crossing. City of Arvada, CDOT Oil and Gas Development Risk: Very Low Priority Ranking: Low From Colorado Oil and Gas Conservation Commission: 1. Share copies of the SWPP with the COGCC and Jefferson County LGD. 2. Participate in COGCC’s LGD program. 3. Periodically review permit applications to determine if they are in the SWPA and if so: • Make comments on the permit application to that effect. • Utilize COGCC GIS map layers to help with evaluating potential impacts. 4.Request CDPHE consultation during an initial permitting process if there are additional concerns. City of Arvada Sand and Gravel Operations Risk: Very Low Priority Ranking: Low 1. Continue to monitor activity at the former sand and gravel operation. City of Arvada Arvada Reservoir Recreation Risk: Moderate Priority Ranking: Medium 1. Continue to monitor activity and enforce existing rules and regulations. 2. Install Drinking Water Protection Area signage at specific locations. City of Arvada Jefferson County Parkway Risk: TBD Priority Ranking: TBD 1. Provide the Jefferson County Parkway Development Authority a copy of the SWPP. 2. Become engaged and stay informed during the planning and construction phases of the Parkway near Arvada Reservoir. 3. Encourage Jefferson County to recognize the City of Arvada SWPAs when making future land use decisions regarding the construction of the Parkway. City of Arvada Sediment Loading from Ralston Reservoir Draining 1. Continue partnership with Denver Water by attending planning meetings associated with the draining of the reservoir for maintenance purposes. City of Arvada, Denver Water ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 56 Risk: Low Priority Ranking: Medium Canal System Chlorides Risk: Low Priority Ranking: Medium 1. Continue to partner with Standley Lake Cities (SLC) in monitoring chlorides in the canal system. 2. Work with local streets departments to decrease chloride amounts in the canal system including snow removal and sand application methods around road bridges. City of Arvada, SLC Security Risk: Moderate Priority Ranking: Medium 1. Continue to conduct daily site visits at the Reservoir. 2. Enhance the security at the Church Ditch diversion and pump station. • Install additional security cameras. 3. Evaluate effectiveness of fence closures at the Reservoir and determine security needs. 4. Install additional no trespassing signage. 5. Evaluate current security measures/practices and enhance security as needed at all areas of concern (reservoir, pump stations, diversions, etc). 6. Distribute SWPP, GIS Shapefiles and Emergency Response Notification Cards to Jefferson County OEM. City of Arvada ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 57 EVALUATING EFFECTIVENESS OF SOURCE WATER PROTECTION PLAN City of Arvada is committed to evaluating the effectiveness of the various source water best management practices that have been implemented. The purpose of evaluating the effectiveness is to determine if the various source water best management practices are being achieved, and if not, what adjustments to the Source Water Protection Plan will be taken in order to achieve the intended outcomes. It is further recommended that this Plan be reviewed at a frequency of once every five years or if circumstances change resulting in the development of new water sources and source water protection areas, or if new risks are identified. City of Arvada is committed to a mutually beneficial partnership with the Colorado Department of Public Health and Environment in making future refinements to their source water assessment and to revise the Source Water Protection Plan accordingly based on any major refinements. ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 58 REFERENCES 2019 Water Quality Report, City of Arvada (2019). Arvada, CO. Retrieved From: Colorado Department of Agriculture. Eurasian watermilfoil. Retrieved from: Colorado Parks and Wildlife. Invasive Concerns: Zebra and Quagga Mussels. Retrieved From: Church Ditch Water Authority. Retrieved from: http://www.churchditch.org/ Copeland, Claudia, “Terrorism and Security Issues Facing the Water Infrastructure Sector” Congressional Research Service, December 2010 http://www.fas.org/sgp/crs/terror/RL32189.pdf Ground Water Protection Council. (2008). Ground Water Report to the Nation: A Call to Action. Oklahoma City, Oklahoma: Ground Water Protection Council. Jefferson County CWPP. Colorado State Forest Service. 2017 Colorado Wildfire Risk Assessment Summary Report: Clear Creek Watershed. October 23, 2019. file:///C:/Users/PHempel/Desktop/CRWA/1%20SWAP_Plans/Jefferson%20County/WM%20NG%20TH/Cl ear%20Creek%20Watershed%20Wildfire%20Risk%20Assessment%20CSFS%202017.pdf Meixner, Tom, Wohlgmuth, Peter, (2004) Wildfire Impacts on Water Quality. Southwest Hydrology. Minnesota Pollution Control Agency (2008). Nutrients: Phosphorus, Nitrogen Sources, Impact on Water Quality - A General Overview. St. Paul, Minnesota. May 2008. Retrieved from: Rapid Watershed Assessment Report: Clear Creek Watershed. Natural Resources Conservation Service. (2007). Lakewood, CO. Sea Grant Minnesota. Retrieved from: http://www.seagrant.umn.edu/ais/watermilfoil USGS (2009). Dreissena Species FAQs, A Closer Look. United States Geological Survey Florida Integrated Science Center. Gainesville, Florida. February 4, 2009. Walsh Environmental Scientists and Engineers. “Garfield County Community Wildfire Protection Plan”. November 2012. Wikipedia. City of Arvada. ---PAGE BREAK--- City of Arvada Source Water Protection Plan Page I 59 APPENDICES2 A. Source Water Assessment Report B. Table A-1 Discrete Contaminant Types C. Table A-2 Discrete Contaminant Types (SIC Related) D. Table B-1 Dispersed Contaminant Types E. Table C-1 Contaminants Associated with Common PSOC’s F. Clear Creek Watershed Wildfire Risk Assessment G. Jefferson County Community Wildfire Protection Plan 2 All appendices are located on the CD version of this SWPP.