9. Upper Clear Creek Watershed

This Technical Appendix to the DRCOG Metro Vision 2020 Clean Water Plan was approved by the Water and Environment Planning Committee on August 25, 2006.

Watershed Description ...... 2 General Setting...... 2 Land Use...... 4 Proposed I 70 Corridor Expansion...... 5 Water Quality Management...... 5 Management Agency Description ...... 5 Stream Standards ...... 6 • Segments and Classifications ...... 6 • Numeric Stream Standards ...... 7 • Impaired Segments ...... 7 Watershed Planning/TMDLs ...... 7 • Standley Lake Agreement on Nutrients...... 8 Urban Lakes...... 11 Nonpoint Source Management ...... 11 Wastewater Treatment Facilities ...... 12 Projected Flows ...... 13 Utility Plan Summaries...... 14 Physical Characteristics...... 18 Capital Improvements ...... 19 Wastewater Permit Limits, Practices and Plans...... 20 Biosolids Practices...... 20 Other Dischargers...... 21 References: ...... 22

Figure 9-1. Upper Clear Creek Stream Segments...... 3 Figure 9-2. DRCOG projected growth in the Upper Clear Creek Watershed to the year 2030 ...... 4 Figure 9-3 Upper Clear Creek Watershed ...... 10 Figure 9-4. Population forecasts for wastewater utility service areas in the Upper Clear Creek watershed...... 13 Figure 9-5. Upper Clear Creek Watershed WUSA & Wastewater Facilities ...... 16

Table 9-1. Upper Clear Creek watershed stream classifications...... 6 Table 9.2. Upper Clear Creek Watershed Metal Impairments ...... 8 Table 9-3. Wastewater Facilities in the Upper Clear Creek Watershed...... 12 Table 9-5: Flows, Actual and Forecasted 2005 – 2030 ...... 14 Table 9-6 Anticipated Capital Improvements...... 19 Table 9-7. Wastewater treatment plant effluent limits...... 20 Table 9-8. Biosolids processing...... 21

Watershed Description

General Setting

The Upper Clear Creek watershed covers an area of about 400 square miles in Gilpin, Clear Creek and Jefferson counties. The headwaters occur along the east side of the continental divide, where elevations reach over 14,000 feet above sea level in the Front Range of Colorado (Figure 9-1). From there, numerous streams coalesce into Clear Creek and flow generally east for about 40 miles to Golden, where Clear Creek becomes part of the South Platte Urban Watershed at an elevation of 5700 feet.

Most of the watershed is composed of variably fractured crystalline basement rocks and thin soils. This geology leads to fracture-flow groundwater systems susceptible to pollution in the event of septic system failure. Large surface flows in narrow canyons can lead to flooding and issues such as sediment loading for water quality. The strongly mineralized geologic characteristics led to numerous and dispersed mining activities over the last 150 years. The resulting placer mining and waste piles exposed large amounts of bedrock and waste material to the environment causing acidification and mobilization of heavy metals into nearby streams. Recently, phosphorous loading has become an increasing concern, especially when released to downstream agencies where nutrients are already a major issue.

The Clear Creek watershed is an important source area for water supplies in the Denver Region. Most of the water results from snowfall in the high country along the Continental Divide, with spring runoff providing water to several large cities along the Front Range, including Thornton, Westminster and Northglenn through storage at Standley Lake. As a result, downstream cities are keenly interested in maintaining high water quality standards in the Upper Clear Creek watershed.

2 Figure 9-1: Upper Clear Creek Stream Segments

3

Land Use

Most land use in the Upper Clear Creek Watershed is public, existing mainly in the National Forest system. The next largest land use is in private land related to patented mining claims. Most of these claims are inactive at this time, having been converted to residential use or gone idle. Some properties are active or recently active.

Working with the local communities, DRCOG has identified six areas in the watershed that are urban and expected to grow in the future. Figure 9-3 shows these Urban Growth Boundary/Area designations, which include the incorporated communities and the new growth area around Clear Creek High School.

While growth in the Upper Clear Creek Watershed is small by regional standards, the topographic effects on growth and water quality are severe. Minor growth can cause major problems to small wastewater treatment plants and construction can disrupt large volumes of bedrock for relatively small gains in constructability. Figure 9-2 provides population and employment projections from DRCOG for the watershed. Population is expected to grow from 29,400 to 40,600 between 2005 and 2030, and employment increases from 22,400 to 27,000 in the same period.

Figure 9-2. DRCOG projected growth in the Upper Clear Creek Watershed to the year 2030

50000 40000

30000 Population 20000 Employment 10000 0 2005 2015 2020 2030

4 Proposed I 70 Corridor Expansion

There are 27 miles of Interstate 70 within the watershed proposed for expansion. The majority of this length of highway runs through the Wastewater Utility Service areas in Clear Creek County. There are several potential ramifications of the proposed highway expansion, including but not limited to the following:

1. Perturbations and interruptions in wastewater utility service 2. Possible need to relocate wastewater service lines and systems 3. Increase in population and employment figures during and after construction 4. Higher demand for wastewater services during and after construction 5. A need for backup wastewater services during highway construction 6. Increased stormwater runoff during and after expansion 7. Higher potential for spills or failures as a result of using temporary wastewater systems during construction.

The communities and residents of the County are concerned about the water quality effects of possible expansion of this major transportation corridor and the potential steps required to mitigate those effects.

Water Quality Management

Management Agency Description

The Upper Clear Creek Watershed Association is the management agency for the watershed. It is involved with ensuring:

• that an effective regional water quality management system is maintained by supporting a stream monitoring program, collecting stream and wastewater facility data, modeling stream quality, assisting with compliance problems;

• cost effective local wastewater management systems within the parameters of the area-wide Clean Water Plan; (Upper Clear Creek Watershed Association Bylaws and Memorandums of Understanding, 2004).

A memorandum of understanding provides the basis and opportunity for joint participation in the association. Eligible association members include:

1. City of Black Hawk 8. Central Clear Creek Sanitation 2. Central City District 3. Town of Empire 9. Black Hawk/Central City Sanitation 4. Town of Georgetown District 5. Town of Silver Plume 10. St. Mary's Glacier Water and 6. City of Idaho Springs Sanitation District 7. City of Golden 11. Clear Creek County 12. Gilpin County

5 13. Jefferson County 17. Schwayder Camp 14. Clear Creek Skiing Corporation 18. CDOT (Eisenhower Tunnel) 15. Climax Molybdenum (Henderson 19. Mount Vernon Country Club Mine and Mill) 20. Saddleback Metropolitan Sanitation 16. Adolph Coors Company District

Stream Standards

The protection of water quality in Colorado involves several steps and a number of agencies. The Colorado Water Quality Control Commission (WQCC) is the primary regulatory body. The WQCC defined a set of uses common to water bodies in the state. These uses are designated for each stream segment. The WQCC also established water quality standards protective of these uses. If these standards are not met, the Water Quality Control Division (WQCD) is required to develop a Total Maximum Daily Load (TMDL) analysis that will return the water body to its full set of uses. This section describes the classifications within the Upper Clear Creek Watershed, the quality of the water bodies, and the efforts currently underway to protect that quality.

• Segments and Classifications

There are 4 main streams in the watershed. Clear Creek itself flows east from the continental divide near Loveland Pass, through the town of Silver Plume to Georgetown, where it is joined by South Clear Creek. From there, if flows northerly to below Empire where the West Fork joins and then on to Idaho Springs. After merging with North Clear Creek, it flows 11 miles to the east end of Golden where it enters the South Platte Urban watershed. Other important tributaries are Chicago Creek, Leavenworth Creek, Fall River, Mill Creek and Beaver Brook.

The WQCC has divided these streams into 17 different segments to reflect the unique uses and water quality within the watershed. Table 9-1 describes the classified uses for the 17 segments. Eleven of the segments are classified for the highest uses: water supply, agriculture, class 1a recreation and class 1 cold water aquatic life.

Table 9-1. Upper Clear Creek watershed stream classifications.

Classified Uses Clear Water Supply Agriculture Recreation Aquatic Life (Cold) Creek Segment Class 1a Class 2 Class 1 Class 2 1- X X X X 2- X X X X 3a- X X X X 3b- X X X X

6 10/2/2006 4- X X X X 5- X X X 6- X X X X 7- X X 8- X X 9a- X X X X 9b- X X X X 10- X X X X 11- X X X X 12- X X X X 13a- X X X X 13b- X X X 19- X X X X

• Numeric Stream Standards

Moat of the 17 segments in the basin have the same physical and biological standards: dissolved oxygen – 6.0 mg/l, pH – 6.5-9.0, fecal coliforms – 200/100 ml, e. coliforms – 126/100 ml. Segment 7 has a pH standard of 6.0-9.0 and segment 8, 3.0-9.0. Segment 7 also has bacterial standards of 2000/100 ml of fecal coliforms and 630/100 ml of e. coli. Standards for inorganic chemicals and metals are consistent with the use classifications (see Attachment A). However, the impaired segments, discussed below, also have temporary modifications of their metals standards.

• Impaired Segments

Of the 17 different stream segments defined by the WQCC (Figure 9-1), eight of these segments are on the 2004 303(d) list of water-quality limited segments requiring TMDL studies. For the majority of these segments, pollutants of concern consist of the metals: Copper, Cadmium, Iron, Manganese, Lead, and Zinc; although on segment 13b of North Clear Creek, aquatic life is also listed as impaired. Specifically, Cadmium impacts segments 9b, 11 and 13b; Copper segments 2, 9a, 9b, and 13b; Iron and Manganese segment 13b; Lead in segments 2, 3b, 9b, 11; and Zinc impairs segments 2, 3a, 3b, 6, 9b, 11, and 13b. These metals require monitoring and on occasion mitigation. Detailed information regarding metals loading comes form the watersheds long monitoring initiative as published in the Upper Clear Creek Watershed Trace-Metals Data Assessment by TDS Consulting of Evergreen, Colorado.

Watershed Planning/TMDLs

Much of the watershed planning in the Upper Clear Creek watershed focuses on metals issues identified in the State’s 303(d) listings. The metals loading problems are discussed in the Nonpoint section of this report concentrate on mining activities. Additionally, concerns regarding nutrients in Standley Lake are addressed through efforts with the point source dischargers in the watershed.

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Table 9.2. Upper Clear Creek Watershed Metal Impairments

Metals Loading

Cd Cu Fe Mn Pb Zn Priority

2, 3a, 3b, Clear Creek 9b, 11, 2, 9a, 9b, 2, 3b, 9b, 13b 13b 6, 9b, 11, Medium Segments 13b 13b 11 13b

• Standley Lake Agreement on Nutrients

In the last 5 years, the construction of the Black Hawk Central City treatment facility and the expansion of the Clear Creek High School treatment plant improved the level of wastewater service and reduced water quality concerns. This was partially brought about by the negotiation and signing of the Standley Lake agreement, commonly known as the Clear Creek / Watershed Agreement. Approved by the WQCC, and the Standley Lake Cities (SLC), a total of twenty-five counties, municipalities, special districts, canal companies, and industries signed on in 1993, establishing a narrative standard for total species of phosphorus and nitrogen on Clear Creek and Standley Lake (Clear Creek / Standley Lake Watershed Agreement). As a result of this standard, entities in the watershed are working to improve the removal of nitrogen and phosphorus from the wastewater plant effluent and Individual Sewage Disposal Systems (ISDS) flowing into the waterways.

Additionally, the Agreement established an extensive monitoring program across the watershed, the interconnecting canals, and Standley Lake. It also included upgrading the watershed’s wastewater plants through improved process controls, implementing modifications where necessary and economically feasible, and developing management plans addressing stormwater quality and quantity, and hazardous spills. Non-point controls included the preparation and adoption of a set of best management practices for the watershed.

The Agreement has been in effect for 11 years. During this time streams, canals, and lakes were extensively monitored for nutrients. The results of data analysis are used in modeling activities and to identify areas in the watershed requiring further remediation or upgrade of wastewater facilities. Some water quality improvements in various reaches of streams or areas of the watershed illustrate progress achieved under the Agreement resulting from cooperation among the entities. However, increases in nitrogen and chlorophyll a levels and periods of anoxia in Standley Lake point to the

8 10/2/2006 need for further attention to water quality. The monitoring activities set forth in the Agreement are ongoing and expected to continue into the future.

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Figure 9-3: Upper Clear Creek Watershed

10 10/2/2006 Urban Lakes

In the Metro Vision 2020 Clean Water Plan, urban lakes were identified as a special class of waterbodies that merited attention from the Colorado Water Quality Control Division. They were usually designated as Class 2 warm water aquatic life lakes and expected to provide limited recreational fishing. This group of waterbodies is no longer listed by the WQCD as a unique set. Therefore, this technical appendix does not provide a listing of such urban lakes.

The WQCD is now reporting on Colorado lakes as part of the biennial report on statewide water quality required by section 305(b) of the Clean Water Act. The report identifies the designated uses of major lakes and notes any impairments to those uses along with the identified sources of impairment. No lakes in the Upper Clear Creek Watershed are included in that listing in the “Status of Water Quality in Colorado 2006” report.

Nonpoint Source Management

Historic mining activities left about 1,600 individual areas of mine tailings. These sites are often located in or near Clear Creek and its tributaries. Erosion of mine waste piles, especially during storms and snowmelt; introduces metals into the water. Considerably more severe impacts include abandoned mine tunnels that continually drain acidic and metal-laden water into Clear Creek. The Clear Creek/Central City Superfund Site was placed on the National Priorities List in 1983 to address the worst of these problems. The Superfund Study Area encompasses the upper Clear Creek Watershed to Golden. However, only about two-dozen properties in Clear Creek and Gilpin counties comprise the Superfund site.

The industrial wastewater treatment plant that became operational in April 1998 in Idaho Springs at the Argo Tunnel shows promising results in mitigating acid and metals loading. The treatment plant is a dual train treatment system with a total treatment capacity of 700 GPM. In 2005 the facility was upgraded from sodium-hydroxide precipitant/high-density sludge treatment process to one utilizing Ca (OH) 2 as a flocculant. Although a NPDES permit for the Argo Tunnel treatment plant was not required, effluent limits for the treatment have been established in the Argo Tunnel Applicable and Relevant and Appropriate Requirements (ARARs) Compliance Document. Monitoring shows an improvement in stream water quality.

A pilot scale constructed wetlands was built in Silver Plume to test whether this technology could prove effective in treating mine drainage emanating from the Burleigh Tunnel. The wetland, after initially promising results, failed to live up to expectations. The EPA and Water Quality Control Division Superfund program is currently reevaluating mitigation techniques for the Burleigh Tunnel discharge. Included in the

11 10/2/2006 reevaluation is a study of the potential impacts of Burleigh Tunnel discharge on the Georgetown Lake.

The EPA and Water Quality Control Division Superfund programs do not currently outline definitive plans for addressing the numerous abandoned mine tunnel discharges included in the Clear Creek Superfund Site. These include discharges from: the Big Five Tunnel in Idaho Springs the Quartz Hill Tunnel in Central City, and the Gregory Incline and National Tunnel in Black Hawk.

A number of mine tailings and waste rock piles have already been cleaned up under the Superfund program and the “Good Samaritan” effort consisting of private clean up activities. In the Spring of 2006, CDPGE and EPA recommended construction of an on- site repository to consolidate mining-related materials associated with remedial actions in the Clear Creek/Central City superfund Study Area. Constructed on mining-impacted property the repository would reduce the need for in-place capping of individual waste piles and tailings eventually resulting in reclamation of impacted lands.

Wastewater Treatment Facilities

At present there are eight major municipal wastewater treatment plants located in the Upper Clear Creek Watershed. Several minor dischargers make up the balance of the treatment plants in the watershed (Table 9-3).

Table 9-3. Wastewater Facilities in the Upper Clear Creek Watershed Major Over 50,000 GPD Minor Under 50,000 GPD 1 Black Hawk/Central City BWBH 2 Central Clear Creek Sanitation District CDOT Eisenhower Tunnel 3 Empire Clear Creek Skiing Corporation 4 Henderson Mine Coors Brewing Corp. 5 Georgetown/Silver Plume Hunter Gold Mining 6 Idaho Springs Beaver Brook/CC School District 7 St. Mary’s Glacier Mount Vernon Country Club 8 Schwayder Camp

The seven major municipal wastewater treatment plants located in the Upper Clear Creek Watershed (Table 9-4) comprise the primary sources of point source pollution. Several minor dischargers make up the balance of the treatment plants in the watershed. Presently a Planning Area is being considered in the proposal of regionalization. Figure 9-5 shows the location of Waste Water Utility Service Areas (WUSA’s), and facilities in the watershed.

12 10/2/2006 Projected Flows

As illustrated in Figure 9-2, the watershed is expected to experience significant growth between 2005 and 2030. However, much of this population is expected to either be sewered out of the watershed (at the Golden/Coors facility) or to be on individual sewage disposal systems (ISDS) such as septic systems. Figure 9-4 shows that slightly less than half of the population in the watershed in both 2005 and 2030 is served by Golden/Coors. Nearly 10,000 people are currently on ISDS. 5,800 additional people will be on ISDS by 2030.

Figure 9-4. Population forecasts for wastewater utility service areas in the Upper Clear Creek watershed

20000

15000

10000

5000 2030 0 2005 Sewered Sewered in basin ISDS out of basin

Table 9-4 provides the expected population and employment growth for the eight major facilities discharging in the watershed. Unique to this watershed, the table also includes forecasts of visitors within the various service areas. Many of these operating agencies are required to size their facilities to serve significant populations of visitors. In fact the number of visitors in 2030 is more than double the number of residents. While visitors are not expected to contribute per capita wastewater flows at the same rate as residents, visitor numbers make up a major factor in the design of these facilities.

13 10/2/2006 Table 9-4. Growth Forecasts by Service Area, 2000-2030

2005 2015 2030 Agency Pop Emp Visitors Pop Emp Visitors Pop Emp Visitors

Beaver Brook 2 11 56 25 44 51 Black Hawk/Central City 664 5130 5130 1448 5812 5812 2232 6492 6492 Central Clear Creek 474 189 754 496 338 1013 535 479 1578 Empire 371 83 185 397 89 249 424 94 388 Georgetown/Silver Plume 1361 940 1739 1729 1059 2337 2098 1177 3641 Henderson Mine 0 488 0 710 0 942 Idaho Springs 1901 940 2898 1947 1007 3895 1994 1074 6068 Saint Mary's Glacier 778 996 1443 0 Total Served 5551 7781 10706 7069 9040 13306 8770 10309 18167

Using the population and employment forecasts illustrated in Table 9-4, anticipated flows for the above-described facilities can be calculated. Table 9-5 below compares expected flows through 2030 with the current capacities at each facility.

Table 9-5: Flows, Actual and Forecasted 2005 – 2030

Agency Hydraulic Flows 2030 Capacity 2005 2015 2030 % of MGD Actual Capacity Beaver Brook 0.02 0.0011 0.006 0.007 34% Black Hawk/Central City 1.13 0.349 0.458 0.567 50% Central Clear Creek 0.1 0.042 0.055 0.072 72% Empire 0.06 0.039 0.042 0.046 77% Georgetown/Silver Plume 0.58 0.273 0.317 0.370 64% Henderson Mine 3.1 2.210 2.221 2.233 72% Idaho Springs 0.6 0.267 0.286 0.320 53% Saint Mary's Glacier 0.60 0.12 0.143 0.181 30%

Total Served 3.07 3.30 3.52 3.79 123%

Based on the above forecasts, the only facility expected to approach capacity during the 2030 planning period is Beaver Brook.

Utility Plan Summaries

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The 1994 Watershed Agreement between Upper Clear Creek Municipalities, the Standley Lake Cities and the WQCC mentioned earlier in this report resulted in numerous water quality improvements. In addition, facilities are addressing the needs of growing service populations and other impacts. Some of the improvements to the various wastewater systems are outlined below. The data and information specified below comes from a review of the Wastewater Utility Plans and the updates to these plans.

CLEAR CREEK COUNTY: The County prepared a study specifically directed to assess the ability of water supply and wastewater plants within the County to meet increased growth and new regulations over the next 20 years. This study evaluated each entity’s raw water supply and wastewater plant. It also looked at the possibility of a countywide sewer system and such a system’s economic impact on the population. The economic impact of meeting a defined nutrient standard for each wastewater plant was identified.

Presently the county is reviewing its ISDS regulations to assist in the cleanup of the stream segments. It has also developed small plant requirements for new subdivision applications and requirements that these plants to be operated professionally.

GILPIN COUNTY: Tightened up on its ISDS regulations and required system improvements in sensitive locations.

BLACK HAWK/ CENTRAL CITY SANITATION DISTRICT: A new wastewater treatment plant with a capacity of 1.125 MGD was built in November of 1994 and became operational in 1995, years after the utility plan was accepted. The improved nutrient removal system employing biological nutrient removal greatly improved the effluent quality entering the stream. Current flows average 0.35 MGD. Recently, the collection system was upgraded to reduce infiltration. The permit requirements are 25 mg/L for the 30-day average of BOD5 and 30 mg/L for TSS. The permit limits ammonia during summer months to between 15 and 18 mg/L.

In 2000, DRCOG accepted the utility plan for the new Black Hawk/Central City facility. Located approximately 5 miles downstream of the previous facility, this plant’s capacity is 2 MGD.

CENTRAL CLEAR CREEK SANITATION DISTRICT: The Central Clear Creek District operates a 0.1 MGD extended aeration plant with tertiary filters. The permit requirements stipulate a 30-day average of 30 mg/L for each of BOD5 and TSS. This plant improved its nutrient removal capabilities through process changes and chemical additions in 1994 and 1995. A new permit

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Figure 9-5: Upper Clear Creek Watershed WUSA & Wastewater Facilities

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(May, 2005) includes an ammonia limit of 25 mg/l but no limit on phosphorus. The plant is currently operating at 0.04-.05 MGD. The District has a DRCOG-approved utility plan.

BEAVER BROOK/CLEAR CREEK SCHOOL DISTRICT: The Clean Water Plan was amended in 2001 to recognize the Beaver Brook facility as a permanent, regional wastewater treatment plant to serve Clear Creek High School and the Beaver Brook Water and Sanitation District. The school district operates a wastewater facility to serve the new high school, which was sized to serve potential adjacent development. The membrane plant has a capacity of 0.02 MGD and at present only operates at about 0.001 MGD. Beaver Brook is expected to reach its designed capacity by 2030, as projected development will have occurred by then.

EMPIRE: The town operates a 0.06 MGD extended aeration plant, with current flows of 0.04-0.05 MGD. The plant is capable of removing phosphorus but is not required to do so in its permit. Empire completed a major upgrade to their WWTP in 1996 that included additional nutrient removal capabilities. The plant was designed for expansion to a capacity of 0.12 MGD by converting the existing aerobic sludge digest basin into an aerations basin, adding a new sludge handling system, and enlarging the chlorine contact chamber.

GEORGETOWN/SILVER PLUME: Georgetown operates a step aeration plant with a permitted capacity of 0.58 MGD and an actual capacity of 0.78 MGD. Silver Plume collects its wastewater and sends it to Georgetown for treatment. Flows currently average 0.34 MGD. The permit requires 30 mg/L for the 30-day average of BOD5 and TSS. The permit, issued in 2005, included an ammonia nitrogen limit that varies by month from a high of 14 mg/L in December to 7.0 mg/L in April. High infiltration and inflow during spring runoff remains a problematic. The town is considering solutions to the address the difficulties posed by seasonal infiltration.

IDAHO SPRINGS: The City of Idaho Springs operates a 0.6 MGD sequencing batch reactor plant serving the City and the Chicago Creek Sanitation District. The permit requirements are 30 mg/L for the 30-day average of BOD5 and TSS. In 2001, the flows through the plant averaged 0.47 MGD.

ST. MARY’S GLACIER WATER AND SANITATION DISTRICT: The St. Mary’s Glacier facility submitted a utility plan for consideration in 1999. DRCOG’s Water Resources Management Advisory Commitee conditionally accepted the plan in October 1999. This plan proposed a replacement facility with dual capacity: 600,000 gpd during snowmelt events and 125,000 gpd for the rest of the year. The District operates a 0.6 MGD activated sludge plant. The permit requirements for the plant are 30 mg/L for the 30- day average of BOD5 and TSS and include ammonia limits varying by month and flow. Flows are currently 0.08-.375 mgd depending on the time of year.

Other facilities in the watershed include three domestic waste treatment plants: the Eisenhower Tunnel facility of CDOT, the Loveland ski area served by the Clear Creek

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Skiing Corporation, and the Camp Schwayder facility. A major industrial facility operates at the Henderson Mine as does a wastewater facility. A second industrial facility operates at Argo mine. A brief description of the wastewater facilities is provided below.

CLEAR CREEK SKIING CORPORATION WWTP: This plant has a capacity of 0.03 MGD. The plant inflow is highly seasonal with low flows in the summer and very high flows throughout the ski season. Upgrades to plant equipment and processes improved nutrient removal and work particularly well during the seasonal changes in flow.

EISENHOWER TUNNEL WWTP: CDOT operates this 0.072 MGD facility. Recent security improvements limited its use to CDOT personnel. The plant implemented the use of live bacterial agent (LBA) to assist in phosphorus removal. LBA, it is found, also helps in nitrogen removal: This plant has a seasonal flow variation hindering adequate nutrient removal.

CAMP SCHWAYDER. This campground is located on the north slope of Mount Evans. The wastewater treatment facility has a hydraulic capacity of 0.009 MGD and average flows of 0.0025 MGD. The plant is identified as a fixed capacity, minor facility, with no plans for expansion.

HENDERSON MINE. Located above Empire, the Henderson Mine is served by a 3.1 MGD capacity wastewater treatment plant with average flows of 20,000 GD as they vary based on employment.

Additionally, development is anticipated in the vicinity of the I-70 and US 40 junction. This may be served by a facility operated by the Douglas Mountain Special District. The service area is expected to include15 homes and up to 10 different businesses.

Physical Characteristics

The facilities in the Upper Clear Creek Watershed are physically separated by both distance and elevation. This section provides information necessary in considering possible consolidation of service. This is a topic under consideration as of Spring 2006 and the subject of a recently tendered Request for Proposal. For a map of facility locations see Figure 5 on page 17.

The highest facilities in the watershed, situated above 11,000 feet, are the Clear Creek Skiing Corp. and Eisenhower Tunnel plants. The tunnel facility is about 1.4 miles west of the ski area facility. The ski area plant is 8.9 miles west of Silver Plume, where it could connect to the collection system for Georgetown.

The Georgetown facility is at an elevation of 8,440 feet. It is approximately 2.6 miles to the I-70/US 40 junction. The elevation here is 8,260 feet. It is another 3.8 miles to the Central Clear Creek facility (or a total of 6.4 miles from Georgetown), but only 0.9 miles

18 10/2/2006 to the closest point of the Central Clear Creek collection system. The Central Clear Creek plant is at an elevation of 7,900 feet.

The distance between Central Clear Creek and the Idaho Springs facility is 6.3 miles and coincides with a drop of nearly 500 feet to an elevation of 7,440 feet. The closest point of the Idaho Springs collection system is 2.6 miles below Central Clear Creek. While the Clear Creek School District is further east, it is also in another drainage, and requires crossing a ridgeline or connecting to a point well into Jefferson County.

The Empire facility is at an elevation of 8,600 feet and is 0.5 miles northwest of the I- 70/US 40 junction.

The other major public facility is the St. Mary’s Glacier plant at an elevation of 10,300 feet. It is 6.4 miles from the facility to the mainstem of Clear Creek with a total distance of 10.5 miles from St. Mary’s Glacier to Idaho Springs.

Capital Improvements

Table 9-6 summarizes the capital improvements anticipated by facilities in the Upper Clear Creek watershed. This table focuses on treatment plant improvements and excludes timing and costs of collection system and lift station improvements. Only the Georgetown/Silver Plume facility currently anticipates any major improvements. Phase I improvements, consisting of new headworks and improved flow measurement devices and a new chlorine contact basin are ongoing. The cost of these improvements came to nearly $647,000. Phase two improvements anticipate the addition of a third aeration basin to remove ammonia and additional sludge storage. The anticipated costs for Phase II are $1.9 M. Presently, phase II improvements are on hold pending the results of the Regional Study for Wastewater Consolidation. The results of this study will help determine the extent of improvements for all facilities in the Basin.

Table 9-6 Anticipated Capital Improvements

Expansion Expected Estimated Cost New Capacity Service Area (mgd) Date ($ millions) (mgd) Beaver Brook None Black Hawk/Central City None Central Clear Creek None Empire None To be To be Georgetown/Silver Plume determined determined Henderson Mine None Idaho Springs None Saint Mary's Glacier None

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Wastewater Permit Limits, Practices and Plans

After requesting a hearing on nutrient standards before the Water Quality Control Commission in 1993, the Standley Lake cities negotiated the Clear Creek Watershed Management Agreement with numerous parties in the Clear Creek and Big Dry Creek drainage areas. The parties to the agreement introduced a narrative standard for Standley Lake calling for the reservoir to maintain a mesotrophic state. This implies a moderate level of biological productivity with the reservoir capable of producing and supporting moderate populations of living organisms (plants, fish, and wildlife) and possessing visibility of 8 to 13 feet. The Colorado Water Quality Control Commission adopted this recommendation in 1994.

Presently, permits for the facilities in the Upper Clear Creek watershed do not include phosphorus limits; the levels of phosphorus are monitored and a limit could be imposed if the quality of Standley Lake deteriorates. Wastewater treatment plant effluent limits are more extensive than those for general permits within the Upper Clear Creek watershed. Tables 9-7 and 9-8 below show the effluent limits for the wastewater treatment plants and the methods for handling biosolids respectively.

Table 9-7. Wastewater treatment plant effluent limits.

Residual Fecal Name Permit BOD TSS NH3-N TP chlorine Coliforms mg/L mg/L mg/L mg/L mg/L #/100mL Beaver Brook CO-0046574 30 30 4.0-7.3 0..011 200 Black Hawk/Central CO-046761 25 30 4.4-15 0.020 355 City COG-588055 30 30 25 0.12 6000 Central Clear Creek Empire CO-0020575 30 30 - 0.5 6000 Georgetown/Silver CO-0027961 30 30 7-20 0.066 3467 Plume Henderson Mine CO-0041467 30 20 - 2.2 6000 Idaho Springs CO-0041068 30 30 - 0.378 5667 CO-0023094 30 30 3.9- 0.01 492 St. Mary’s Glacier 31.8

Biosolids Practices

A by-product of wastewater treatment is biosolids. Almost all large wastewater treatment plants have some plan in place to process their biosolid waste. DRCOG recognizes and supports the economic and environmental benefits of recycling biosolids, and appropriate council policy documents will recognize the value of biosolids recycling. The Clean Water Plan’s biosolid positions are as follows:

1. Public health and environmental quality are protected under federal and state biosolids regulations. The council encourages member governments not to adopt

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local public health regulations for biosolids that are more stringent or restrictive than federal or state regulations.

2. The council encourages the practical and beneficial land application of biosolids in the DRCOG region. Member governments with land use authority should regulate biosolids disposal through the zoning and platting process. Local regulations should focus on transportation, aesthetics and land use issues.

3. The council does not support any biosolids disposal practices that do not attempt to beneficially reuse this valuable resource.

Table 9-8 summarizes the biosolids processing practices of the three facilities in the Big Dry Creek watershed. These efforts are consistent with the regional policy.

Table 9-8. Biosolids processing

Name Permit Biosolids Processing Disposal CO-0046574 Extended Aerobic Trucked off Beaver Brook processing in A- basins CO-0023949 Aerobic digester, Land application/ Black Hawk/Central aerated mine tailing City composting reclamation COG-588055 Aerobic digester On –site Central Clear Creek landscaping Empire CO-0020575 Aerobic Digester Trucked off Georgetown/Silver CO-0027961 Aerobic Digester Trucked off Plume CO-0041467 Aerobic Digester Stored on Henderson Mine site, then land filled Idaho Springs CO-0041068 Aerobic Digester Trucked off CO-0023094 Extended Aerobic On –site storage processing in A- Saint Mary's Glacier basins

Other Dischargers

The WQCD has issued 8 other discharge permits in the watershed for facilities such as water treatment plants, industrial dischargers and small treatment plants. Stormwater permits for construction activities are also issued by the Division but no summary is readily available for the watershed.

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References:

Clear Creek / Standley Lake Watershed Agreement

Waste Water Utility Plans and Updates

Upper Clear Creek Watershed Association Bylaws and Memorandums of Understanding, 2004.

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