PROJECTS

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Used ESRI ArcGIS to assess relative productivity in Panama Reservoir, an off-channel reservoir in Boulder County, Colorado. Chlorophyll‑a concentrations were represented by Landsat‑derived ratios of green (B3) to blue (B2) satellite imagery bands to map spatial patterns of long‑term qualitative algal trends. Higher B3/B2 ratios indicate greater phytoplankton abundance and correspond to more degraded water quality than lower ratios.These GIS findings were corroborated by source nutrient‑loading and water‑residence‑time analyses, which altogether informed recommendations to mitigate water‑quality risks under assumed worst‑case reservoir operating scenarios. Recommendations emphasized management strategies to protect a downstream drinking‑water supply from potential negative impacts of poor water quality discharged from the reservoir. The evaluation  provided qualitative and quantitative evidence used in a water‑rights substitution and exchange case. 

Created an enhanced, weight‑of‑evidence approach to evaluate water quality in Eagle Park Reservoir, Eagle County, Colorado, and determine compliance with protective covenants established when the reservoir was acquired in 1998.  Analyses targeted areas of adjacent mine property that could pose risks to reservoir water quality and combined multiple, complementary lines of evidence to provide targeted insights into surface‑water and groundwater contaminant sources. Considered collectively, these analyses increase resolution and confidence in assessing potential risks of water‑quality degradation. As a result, reservoir managers can better mitigate risks, prioritize areas for further investigation, and prevent future degradation by addressing areas of concern before they affect the reservoir.

Developed and implemented site-specific methods to evaluate the feasibility of both non-point-to-point, and point-to-point nutrient trades under Regulation No. 85. For non‑point‑to‑point trade, evaluated whether trade offsets could generate nutrient credits under the Voluntary Incentive Program to justify extending a wastewater treatment facility’s (WWTF) permit compliance schedule to meet future nutrient limits. For point‑to‑point trade, established proposal for alternative effluent concentration-batsed nutrient limits for three interconnected WWTFs while maintaining the combined allowable total median nutrient loads required by Regulation 85. The approaches ensured regulatory compliance, preserved aggregate load allowances, met trade ratios, and provided defensible frameworks for establishing offsets and negotiating permit limits and compliance schedules.

Conducted an analysis demonstrating that a discharge was not a potentially significant contributor of pollutants to receiving waters according to Clean Water Policy 14 (CWP 14). Evaluations considered measured pollutant concentrations in the discharge, applicable receiving‑water standards, nearby groundwater contamination sources, discharge flow rate, existing water quality and assimilative capacity, and environmental‑justice concerns adjacent to the discharge location. The technical findings supported a determination that the discharge was not a potentially significant contributor of pollutants and justified removing the existing discharge permit in favor of coverage under CWP 14, which applies to certain dewatering discharges in Colorado for which the WQCD does not intend to actively enforce permit coverage while the policy is in effect. The analysis documented the rationale for coverage under the policy and provided defensible technical docmentation to support the regulatory decision.

Synthesized temperature data and conducted anthropogenic source analysis for a Use Attainability Analysis supporting site‑specific standards proposals for 3 stream segments in the Eagle River watershed, Colorado. Assessed spatial and temporal thermal regimes and compliance with table value standards, quantified reach‑scale heat loading from dischargers, and evaluated urban‑runoff effects on stream temperatures. Extensive stakeholder outreach and negotiations with state and federal agencies and local partners informed final proposals and were critical to their success. Integration of temperatue and aquatic life analyses culminated in site-speciic standards adopted through the Water Quality Control Commission's Regulation 33 rulemaking. The final standards acknowledge natural temperature profiles, protect aquatic life, and help prevent unsupported non-compliance listings and discharge permit limitations that require costly infrastructure without providing a water quality benefit.

The primary objective of the project was to develop a stream model capable of quantifying nutrient‑related impacts of effluent discharge on water quality in the reach below the Paseo Real Wastewater Treatment Plant (WWTP) in Santa Fe, New Mexico. The QUAL2Kw water‑quality model was selected for this task. Findings from the study supported regulatory goals related to discharge permitting, informed evaluations of temporary standard alternatives under consideration for the Paseo Real WWTP, and provided a foundation for TMDL development. The project also included development of a water quality and algae sampling and analysis plan; collection of field monitoring and flow measurement data, continuous data collection and discrete water‑quality sampling at key locations along the river; comprehensive data analysis and statistical summaries; and completion of a flow‑transect study to support model calibration and scenario evaluation.

Compiled, QA/QCed, analyzed, and summarized baseline water‑quality data collected during annual September synoptic sampling events (2008–2021) at 36 monitoring stations in the mainstems and tributaries of Gore Creek and the Eagle River, Colorado. The report integrates water chemistry data with watershed characteristics, land uses, runoff impacts including urban‑stream impairment, 303(d) listings, discharger contributions, and biological health to characterize existing conditions and flag potential areas of concern. Concentrations and loading for 24 parameters were evaluated across seven upstream‑to‑downstream reaches, and summary statistics and key observations were developed for each monitoring site. Baseline monitoring continues to support scientific, permitting, planning, and management needs for the Eagle River Water & Sanitation District and local stakeholders.

Used ESRI ArcGIS to estimate basin‑wide nutrient (nitrogen and phosphorus) reduction through attenuation from Individual Septic Disposal Systems (ISDSs) to Cherry Creek Basin, Colorado surface waters.The Method for Estimating Attenuation from Septic Systems (MEANSS), developed by the Montana Department of Environmental Quality, provided the analytical framework for the GIS assessment. Nutrient delivery from each ISDS was quantified based on discharge, soil characteristics, and distance to the receiving water. By integrating these components in a spatial environment, the analysis quantified attenuation‑based load reductions for more than 7,000 permitted ISDSs across the basin. The nutrient load (lbs/year) reaching surface waters was calculated by subtracting  the total attenuated load reduction from the total ISDS-generated load. Results supported water‑quality management planning in the Cherry Creek Basin, which is subject to a nutrient‑control regulation.

The project applied the QUAL2Kw model to evaluate nutrient fate and transport in the Eagle River watershed, assess model sensitivity and performance, and support nutrient management planning for the Eagle River Water & Sanitation District’s 3 WWTFs. Work included identifying cost‑effective nutrient‑trading strategies under Regulations 85 and 31, developing approaches for evaluating trading options using model outputs, and testing scenarios consistent with Colorado’s regulatory and trading frameworks. The Bubble Permitting approach was also evaluated to calculate and allocate nutrient loads among the facilities under a Memorandum of Understanding between ERWSD and the State of Colorado, allowing load increases at one facility when matched by reductions at another to optimize compliance costs.

Provide permit review, renewal, and compliance services for individual and general discharge permits. Work includes preparing permit applications, developing supporting technical analyses, and coordinating with the WQCD. Experience includes permit adjudication, developing and assessing preliminary effluent limits, copper translator limit evaluations, compliance schedule extensions, permit modifications, development of water‑quality sampling and analysis programs to support renewal needs, and analyses of alternative degradation limits and discharger‑specific variances. Clients include the Eagle River Water & Sanitation District, Mount Crested Butte Water & Sanitation District, Town of Crested Butte, Town of Erie, Central Clear Creek Sanitation District, Walden Water & Sanitation District, the Steamboat Mountain School, and a major water provider (name confidential).

Support spans a range of federal and Colorado water‑quality frameworks, with an emphasis on clear, defensible technical analyses. Work includes participation in Water Quality Control Commission hearings (e.g., Regulations 85, 31,33, 61,71,93), from technical review through preparation of hearing documents and delivering testimony. Additional support covers development of site‑specific standards, alternative permit standards, variances, and implementation proposals that protect water resources while avoiding unnecessary regulation of dischargers. Representation of regulated entities also includes TMDL review and interpretation, along with participation in multiple standards, policy, and technical advisory workgroups to help ensure that regulatory revisions and implementation proposals are reasonable and technically sound. Stakeholder outreach is integrated throughout these activities, allowing technical findings to be communicated effectively to agencies, watershed groups, and community partners.