STATE OF THE WATERSHED Annual Newsletter of the Big Dry Creek Watershed Association December 2013

Transcription

1 STATE OF THE WATERSHED Annual Newsletter of the Big Dry Creek Watershed Association December 2013 Volume 15 Big Dry Creek 2012 Water Quality Review Inside this issue: A key focus of the Big Dry Creek Watershed Association (BDCWA) is annual assessment of water quality conditions in Big Dry Creek. In the spring of each year, BDCWA uploads the results of the instream water quality monitoring program into a longterm water quality database and compares the results to applicable water quality standards for Big Dry Creek. Findings are documented in an annual water quality report that is presented and discussed at the March BDCWA public meeting and then posted to the BDCWA website. This brief article highlights some of the key findings of the 2013 water quality analysis, which included samples collected and analyzed during 2012 by staff from the City and County of Broomfield and the Cities of Northglenn, Thornton, and Westminster. In 2012, water quality samples were collected and analyzed for a variety of constituents. Metals were monitored on a quarterly basis with the exception of selenium, which was monitored monthly. All other constituents were monitored on a monthly basis. The Cities and BDCWA also fund operation of the U.S. Geological Survey (USGS) gauging station at Westminster behind Front Range Community College. Key findings and recommendations regarding Big Dry Creek water quality and aquatic life conditions based on analysis of the 2012 data set include: Water quality in Big Dry Creek attained stream standards for currently assigned stream standards, with the exception of E. coli. (Continued on page 2) Big Dry Creek 2012 Water Quality Review CLEAN Center Underway at Colorado State University The Great Flood of Macroinvertebrate Data and MMI Analysis BMW Urban Waters Grant Campaign Broomfield Awarded $1 Million Grant What is the Big Dry Creek Watershed Association? All Watershed Association general membership meetings are open to the public Meetings are generally held on a quarterly basis in March, May, September and December. For More Information on the Next Watershed Meeting, contact Jane Clary: or visit our website: The Big Dry Creek Watershed Association is a 501(c)(3) corporation. Big Dry Creek in November 2012 near Thorncreek Golf Course.

2 2 State of the Watershed: Newsletter of the Big Dry Creek Watershed Association (Big Dry Creek 2012 Water Quality Review, Continued from page 1) Big Dry Creek did not meet the E. coli standard during 2012 using current Colorado Water Quality Control Division (CWQCD) assessment procedures, which assess attainment on a bimonthly interval. E. coli exceeds the stream standard during all bimonthly intervals except November- December. When considering the last fiveyear period, the standard is attained during the non-recreation season, but exceeded during the recreation season (May-June, July-August and September-October intervals). A Total Maximum Daily Load (TMDL) process has been initiated by the CWQCD and EPA for Big Dry Creek with regard to E. coli. BDCWA is working cooperatively with the CWQCD and EPA to ensure that the most complete and scientifically sound data set and assumptions are used in this process. Special studies related to sources of E. coli in the watershed were conducted by Wright Water Engineers and BDCWA during 2007 and 2008 and provided to the CWQCD. A draft TMDL is anticipated during For the most recent 5-year analysis period ( ), Big Dry Creek attained its sitespecific selenium standard for both the irrigation and non-irrigation seasons; however, the stream is currently listed on the (d) list of impaired waters for selenium. Based on review of the historic data set, Big Dry Creek is expected to cycle on and off of the 303(d) List, unless the site-specific standard is adjusted to allow a margin for year-to-year variability based on natural conditions and irrigation release patterns from Standley Lake. Big Dry Creek does not attain the interim warm water instream nitrogen and phosphorus values adopted by the Colorado Water Quality Control Commission (CWQCC) in Although these values would not be expected to be adopted as stream standards for Big Dry Creek for 10 years or more, ad- (Continued on page 3)

3 State of the Watershed: Newsletter of the Big Dry Creek Watershed Association 3 (Continued from page 2) dressing nutrient sources on Big Dry Creek should be an increasing area of focus for BDCWA. Phosphorus concentrations and loads to Big Dry Creek are decreasing due to enhanced treatment processes at the Broomfield and Westminster WWTPs, along with reuse programs that continue to be implemented at these WWTPs. (See figure below.) Despite these substantial operational improvements, the stream would not meet the Regulation 31 interim total phosphorus values from I-25 to the confluence with the South Platte River. Big Dry Creek currently attains aquatic life uses, based on calculation of MMI scores in accordance with CWQCC s Aquatic Life Use Attainment Policy Scores were calculated at six biological monitoring locations for fall monitoring conducted during 2008, 2010, and MMI scores vary substantially, both temporally and spatially. (See page 6 for more information.) Average streamflows during 2012 were among the lowest in the period of record for both stream gages on Big Dry Creek. In February 2013, the Big Dry Creek Sampling and Analysis Plan (SAP) was updated to facilitate compliance with the Regulation 85 nutrient monitoring requirements, which include increased instream monitoring relative to WWTP Properly disposing of pet waste is an easy way to help to reduce bacteria loading to Big Dry Creek. discharges. Changes to the monitoring program include analyses for total Kjeldahl nitrogen to enable calculation of total nitrogen, as well as additional analysis of flow for purposes of estimating instream nutrient loads upstream and downstream of WWTP discharges. Changes to the field QC program for nutrients have also been implemented in the 2013 SAP. For a complete copy of the 2012 Annual Report, see Estimated Big Dry Creek Total Phosphorus Load for Big Dry Creek Declining Over Time Near the Confluence with the South Platte River

4 4 State of the Watershed: Newsletter of the Big Dry Creek Watershed Association CLEAN Center Underway at Colorado State University In 2013, BDCWA provided a letter of support for a Colorado State University (CSU) led effort to develop a solution-oriented nutrient center (CLEAN Center) under a major EPA STAR grant program. CLEAN stands for Center for Comprehensive, Optimal and Effective Abatement of Nutrients. EPA selected CSU to lead a multistakeholder effort to study and control the sources of excess nutrients in wastewater, stormwater, agricultural water, and natural systems. The Center activities will connect natural and physical systems, human actions, and policy to create innovative solutions to nutrient pollution problems. Sustainable nitrogen (N) and phosphorus (P) management solutions for restoring watershed systems and attaining designated uses will be developed and demonstrated. These sustainable solutions will integrate abatement strategies for urban, agricultural, and riparian systems, and effective policy instruments (incentives and market-based approaches) that facilitate trading among sectors, provide equity along water systems, increase chance of adoption, and minimize costs. The mission of the CLEAN center is to create knowledge, build capacity, and forge collaboration to develop and demonstrate sustainable solutions for reduction of nutrient pollution in the nation's water resources. BDCWA will look forward to participating in the CLEAN Center efforts as the project moves forward. Key projects planned by CSU and its partners include: Understand the Physical System: Project 1: Achieving Nutrient Reductions through Innovative Approaches for Wastewater Management and Water Demand Reduction Project 2: Urban Stormwater Management- Evaluation of Simple Retrofits/Design Enhancements and Development of Simple Assessment Tools Project 3: Nutrient Reductions in Agricultural Watersheds: Intentional Planning, Implementation, and Maintenance Project 4: Fluvial Instability and Riparian Degradation: Evaluating and Reducing Nutrient Loading from Channel-Riparian Interfaces Understand People and Policy: Project 5: Effective Incentives and Viable Trans- Sectoral Trading Strategies Enhance the Decision Making Process: Project 6: Accessible Nutrient Data, Analysis and Modeling Dashboard for the Nation Project 7: Assessing Nutrient Management Tradeoff and Targets under Uncertainty For more information on the CLEAN Center, see 20Overview.pdf.

5 State of the Watershed: Newsletter of the Big Dry Creek Watershed Association 5 The Great Flood of 2013 Colorado Boulevard crossing at Big Dry Creek below the Union Pacific Railroad during the September 2013 flood. In September 2013, Coloradoans were reminded of the power of nature during a multi-day rainfall event. Communities along Big Dry Creek experienced significant damage to road infrastructure, businesses, homes, and agricultural lands. HDSC maps can be accessed at aep_storm_analysis/8_colorado_2013.pdf. The National Oceanic and Atmospheric Administration s National Weather Service Hydrometeorological Design Studies Center (HDSC) developed maps showing annual exceedance probabilities (AEPs) of the worst case rainfall for the Colorado event that started on September 9, The AEP is the probability of exceeding a given amount of rainfall at least once in any given year at a given location. It is an indicator of the rarity of amounts of rainfall and is used as the basis of hydrologic design and regulation. The multiday storm event delivered total rainfall amounts that exceeded 15 inches in some locations as it slowly moved through the area and caused extensive river flooding (HDSC 2013). The HDSC map series shows areas that experienced rainfall magnitudes with AEPs ranging from 1/10 (10%) to smaller than 1/1000 (0.1% ) for 24- hour, 48-hour, and 7-day durations, respectively. Portions of the Big Dry Creek watershed experienced rainfall with an AEP of less than 0.1% for these rainfall durations. A complete set of the

6 6 State of the Watershed: Newsletter of the Big Dry Creek Watershed Association 2012 Macroinvertebrate Data and MMI Analysis The Big Dry Creek Watershed Association (BDCWA) sponsors biannual biological monitoring on Big Dry Creek, which includes both fish and macroinvertebrates (bugs) at six long-term monitoring sites on Big Dry Creek. These monitoring locations include sites in the Westminster Open Space upstream of municipal wastewater treatment plant (WWTP) discharges, below WWTP discharges and locations in the agricultural portion of Weld County. The monitoring program has been conducted for BDCWA by Aquatics Associates since In 2010, the Colorado Water Quality Control Commission (CWQCC) adopted Policy 10-1, which provides for the evaluation of the biotic integrity of streams through use of a multi-metric index (MMI) calibrated for the State of Colorado. The policy established aquatic life use-attainment thresholds for three separate stream biotypes, which include Transition (Biotype 1), Mountain (Biotype 2), and Plains & Xeric (Biotype 3). The Big Dry Creek study sites are all designated as Biotype 3. The thresholds for Biotype 3 streams are MMI >37 for use attainment and MMI <22 for impairment. MMI scores >44 for Biotype 3 streams indicate a high scoring water (HSW) and any drop in HSW scores of 22 points or more for samples collected 12 or more months apart within a 5-year span of time may indicate impairment. Failure to meet use attainment thresholds for streams in their particular biotype may result in the affected segment(s) being listed as provisionally impaired for aquatic life on the 303(d) List. BDCWA s biannual macroinvertebrate monitoring program provides data appropriate for calculation of MMI scores and assessment of aquatic life use attainment in accordance with Policy Results of the MMI analyses for the macroinvertebrate samples collected at the six BDC sites in the fall of 2008, 2010, and 2012 are shown in the figure below. All samples for the three years met or were better than the impairment threshold of MMI >22 (22.1 or higher), and over the three sampling years, no consistent upward or downward trends were noted. Over the three sampling years, 12 of the 18 total samples collected were classified as HSW with MMIs >44. Based on the MMI results for the six sampling sites for the three most recent years analyzed, the aquatic macroinvertebrate community in Big Dry Creek is generally healthy and meets MMI useattainment criteria for aquatic life in Class 2 warm water streams. Red lines bracket the attainment and impairment thresholds under Policy (higher scores indicate better aquatic health).

7 State of the Watershed: Newsletter of the Big Dry Creek Watershed Association 7 BMW Urban Waters Grant Campaign The Big Dry Creek Watershed Association participates in regional collaborative efforts to improve water quality. One such regional effort is a new water quality campaign initiated by the Barr Milton Watershed Association (BMW). In June of 2012, BMW received a grant from EPA to bring together water interests in the Denver Metro area to develop and test clean water messages. Over the past 15 months, BMW grant partners have met seven times. Starting with a review of surveys conducted by the Colorado Water Conservation Board and the Greenway Foundation/PURE effort, along with conducting five focus groups, a baseline of current water awareness was established. Among the conclusions of the surveys and focus groups are: Water quality is not on the public s radar. People are willing to participate in keeping water clean once they re aware there is a problem. The trusted messenger for water quality messages are water quality professionals and environmental/conservation groups. Working with the grant partners, messages about changing two behaviors to protect water quality have Logo for water quality educational campaign developed under the Urban Waters Grant. been developed. The behaviors are picking up after your dog and using phosphorus free fertilizer on lawns. Equipped with baseline information and a focus on just two behaviors, BMW hired a marketing firm to develop a logo, tagline and messages. The messages are in draft form and currently in the testing phase. Contact Amy Conklin at amy.conklin@comcast.net for a presentation of the messaging materials or for more information. Broomfield Awarded $1 Million Grant In 2012, the Colorado Water Quality Control Commission (CWQCC) adopted Regulation 85, Nutrients Management Control, which requires larger domestic wastewater treatment facilities to meet more stringent effluent limits for nutrients. Following the establishment of CWQCC Regulation 85 and understanding the financial impact that the new standards were going to place on larger communities, the Colorado General Assembly passed HB , Nutrients Grant Fund, to provide grant funding assistance for communities that are subject to WQCC Regulation 85. In July 2013, Broomfield applied for and received a design and construction grant for WWTP improvements based on findings from a nutrient treatment and optimization study that was conducted at the facility in early 2013 by Tetra Tech. The study determined that Broomfield could achieve the CWQCC Regulation 85 nutrient standards through additional capital improvements totaling approximately $4 million. The additional improvements include: Constructing a gravity thickener for primary sludge treatment; Replacing existing multi-stage centrifugal blowers with new frictionless high-speed turbo blowers to regulate air flow rates; and Installing additional piping to improve process recirculation. Under the grant, Broomfield will be completing the permitting, engineering design, construction, and startup of the new treatment processes by May 31, 2016.

8 What is the Big Dry Creek Watershed Association? The Big Dry Creek Watershed Association (BDCWA) is a non-profit corporation consisting of individuals and entities who dedicate time and resources to developing a sound scientific understanding of water quality, flow, aquatic life and habitat conditions in the Big Dry Creek watershed and act to improve these conditions. The Big Dry Creek Partnership, which included the City and County of Broomfield, the Cities of Northglenn and Westminster, and Rocky Flats Environmental Technology Site (RFETS), founded the BDCWA in These entities have been heavily involved in monitoring stream conditions for many years. Since 1997, the Association has expanded to include representatives from other cities, counties, farmers, ditch companies, citizens and regulatory and resource agencies. The BDCWA is open to those interested in cooperatively working towards understanding and prioritizing efforts to improve basin conditions. In 2004, the BDCWA formed a non-profit corporation with a Board of Directors currently consisting of representatives of the Cities of Westminster and Northglenn, the City and County of Broomfield, Weld County and Adams County. Activities of the BDCWA during the last fifteen years have been funded through the contributions from these entities, as well as the City of Thornton, U.S. Department of Energy, the Woman Creek Reservoir Authority, the Colorado Water Conservation Board, the U.S. Environmental Protection Agency s 319 program (as administered by the Colorado Department of Public Health and Environment) and the Regional Geographic Initiative grant program. For more information on the Big Dry Creek Watershed Association, please visit the BDCWA s web page at or contact Jane Clary, Watershed Coordinator, Wright Water Engineers, Inc., or clary@wrightwater.com. Big Dry Creek Watershed Association c/o Wright Water Engineers, Inc W. 26th Ave., Suite 100A Denver, CO Phone: Fax: clary@wrightwater.com