Division of Water Quality

Utah’s Water Quality Monitoring Program

On this page: Water quality monitoring and assessment  |  Our monitoring programs  |  Assessment: How we decide if waters are healthy

Water quality monitoring and assessment

The Division of Water Quality regularly monitors and assesses Utah’s streams, rivers, lakes, and reservoirs to see whether they are supporting their designated beneficial uses, such as drinking water, recreation, aquatic life, and agricultural use (irrigation and stock watering). Beneficial uses are the official ways a waterbody is intended to be used and they guide how we set and apply Utah’s water quality standards.

Beneficial uses include:

  • Drinking water
  • Recreation (swimming, boating, and fishing)
  • Aquatic wildlife
  • Agricultural use (irrigation and stock watering)

For more information on statewide conditions, see the State of Utah’s Integrated Report 305(b) Report to Congress, individual watershed assessments, and the 303(d) List of impaired waters on our Publications and Rules page.

We use water quality data to:

  • Identify impaired waterbodies (waters that are not meeting standards)
  • Set water quality goals for projects that restore or protect water quality
  • Support permitting, planning, and public health decisions

Find more detailed information about our monitoring projects in the Utah Strategic Monitoring Plan.

Our monitoring programs

We organize our monitoring and assessment work into several programs that collect different types of data and answer different questions about Utah’s waters. Together, these programs support permitting, Total Maximum Daily Load (TMDL) development, watershed planning, and public health protection.

Major monitoring program areas include:

  • Ambient monitoring (streams and lakes)
  • Biological monitoring (UCASE and NARS)
  • Point source and wasteload monitoring (UPDES-related)
  • Nonpoint source monitoring
  • Cooperative monitoring
  • Benthic macroinvertebrate sampling
  • Recreation monitoring (HABs and E. coli)

Ambient monitoring

We use ambient monitoring to provide the core water quality data needed for many of our programs, including nonpoint source monitoring, TMDL development, the Integrated Report, wasteload allocation, status and trends analyses, compliance sampling, and watershed health evaluations. Ambient monitoring includes two main programs:

  • Ambient stream monitoring
  • Ambient lake monitoring

Ambient stream monitoring

In our ambient stream monitoring program, we collect:

  • Basic water chemistry, such as metals, nutrients, and inorganic parameters
  • Additional tests, where needed, such as E. coli, biochemical oxygen demand (BOD), and chlorophyll-a
  • Field measurements taken on site, including pH, dissolved oxygen, conductivity, temperature, and streamflow (discharge)

We divide Utah into six monitoring basins and rotate “intensive runs” through these basins on a planned schedule, collecting samples at each site once a month for a year before moving to the next basin. This rotating-basin approach helps us determine whether streams are meeting their beneficial uses and provides the assessment data needed to identify problems and evaluate potential solutions.

Ambient lake monitoring

In our ambient lake monitoring program, we use a similar rotating-basin approach for lakes and reservoirs. We routinely monitor approximately 130 lakes for water quality and typically:

  • Sample each waterbody at least twice a year when that basin is the focus of monitoring
  • Sample some lakes more often when data needs are high

This program is designed to:

  • Determine existing lake water quality conditions
  • Evaluate trends over time
  • Protect and enhance lake water quality
  • Determine whether lakes are supporting their beneficial uses

We typically collect basic water chemistry data (similar to streams) and biological indicators such as phytoplankton.

Biological monitoring

Our biological monitoring program evaluates the health of rivers and streams using biological, physical, and chemical indicators. Biological data help show how aquatic communities respond to pollutants and other stressors over time and complement our water chemistry data.

Utah Comprehensive Assessment of Stream Ecosystems (UCASE)

Through the Utah Comprehensive Assessment of Stream Ecosystems (UCASE), we use probabilistic surveys and targeted monitoring to characterize and track the health of rivers and streams statewide. At each site, we collect:

  • Biological data, such as fish surveys, fish tissue analysis, macroinvertebrates, and periphyton
  • Physical habitat data, such as stream geometry and habitat features
  • Water chemistry data

We use this combined information to evaluate overall stream condition and support decisions about beneficial use support.

National Aquatic Resource Surveys (NARS)

We also participate in the National Aquatic Resource Surveys (NARS), national studies coordinated by the U.S. Environmental Protection Agency (EPA) and conducted in partnership with states and tribes. These surveys use a statistical design to assess the condition of the nation’s lakes, rivers and streams, wetlands, and coastal waters. Utah has participated in NARS since 2007, using EPA funding to expand our monitoring programs.

NARS includes five resource areas:

  • Lakes – National Lakes Assessment (NLA)
  • Wadeable streams – National Rivers and Streams Assessment (NRSA)
  • Non-wadeable streams – National Rivers and Streams Assessment (NRSA)
  • Wetlands – National Wetlands Condition Assessment (NWCA)
  • Coastal waters – National Coastal Condition Assessment (NCCA)

Point source and wasteload monitoring

Through the Utah Pollutant Discharge Elimination System (UPDES) program, we regulate discharges to waters of the state using permits that set effluent limits and monitoring requirements. Facilities covered by UPDES permits must submit Discharge Monitoring Reports (DMRs) so we can verify compliance with permit limits (Utah Administrative Code R317-2).

We also collect our own compliance samples at permitted facilities to:

  • Support municipal and industrial compliance monitoring
  • Help establish wasteload discharge limits
  • Confirm that TMDL endpoints and water quality standards are being met

We continue to adapt our compliance monitoring so we can better support these programs over time.

For more information, visit our wasteload analysis page.

Nonpoint source monitoring

Nonpoint source (NPS) monitoring focuses on pollution that does not come from a single discharge pipe, such as runoff from farms, rangelands, or urban areas. We use NPS monitoring data to understand background water quality conditions and to evaluate how effective watershed projects funded through the Nonpoint Source Program are.

In addition to traditional water chemistry sampling, we often collect information on stream function and biology, such as:

  • Riparian zone vegetation
  • Stream shape and form (geomorphology)
  • Fish habitat
  • Fish populations

We use this information to evaluate how best management practices (BMPs) are working in nonpoint source watersheds. Nonpoint source projects occur throughout the state.

Learn more on our Nonpoint Source Program page.

Cooperative monitoring

We use our Cooperative Monitoring Program to expand the monitoring network by working with other government entities to collect credible water quality data. Our cooperative partners include:

  • Federal agencies (U.S. Forest Service, Bureau of Land Management, National Park Service)
  • State agencies (Division of Wildlife Resources and others)
  • County and local agencies

Under this program, we:

  • Provide training, sampling supplies, equipment, and laboratory analysis
  • Administer quality assurance and standard operating procedures for participating agencies

We also work with our District Engineers and watershed coordinators to collect the frequent E. coli samples needed to calculate geometric means and properly assess recreational uses. In addition, we coordinate with DEQ District Engineers to respond to emergencies and spills that may affect water quality.

Benthic macroinvertebrate sampling

We collect benthic macroinvertebrate samples (bottom-dwelling aquatic insects and other invertebrates) primarily under the UCASE project, but also for other projects. Macroinvertebrates are sensitive indicators of water quality and help us evaluate stream health in ways that complement our water chemistry data.

Because these organisms live in the water for most of their life cycle, they integrate the effects of multiple stressors over time. This gives us a record of past and intermittent conditions that a single water sample might miss.

Recreation monitoring

We monitor popular recreational waters for two main public health concerns:

  • Harmful algal blooms (HABs), often caused by cyanobacteria
  • E. coli in high-contact recreation waters

Harmful algal blooms (HABs)

Harmful algal blooms (HABs) are increasingly common in Utah’s lakes and reservoirs. We monitor HABs so water managers can:

  • Understand bloom conditions and the dynamics of each waterbody
  • Develop effective management strategies
  • Target resources to control and respond to blooms

HABs can affect recreational beneficial uses and may lead to waterbody impairments and TMDL development.

E. coli sampling

We also manage an E. coli monitoring program to protect recreational waters used for swimming and other high-contact activities. We use this program to:

  • Support long-term assessment and TMDL development
  • Conduct short-term advisory monitoring at priority recreation sites

Each spring, we work with local partners to identify priority locations for high-contact recreation. We then coordinate monitoring from May through October with:

  • DWQ field crews
  • Local health departments
  • Additional cooperators

We provide guidance to local health departments on advisory thresholds and follow-up monitoring through the Waterborne Pathogen Advisory Program.

You can find more information on our Recreational Water Quality page.

Assessment: How we decide if waters are healthy

We evaluate beneficial use support (with the assessment methods described in Utah’s Integrated Report on Water Quality) primarily by comparing water quality data to Utah’s water quality standards, which define numeric and narrative criteria needed to protect designated uses. We also use supporting information such as:

  • Riparian habitat evaluations
  • Stream channel habitat evaluations
  • Benthic macroinvertebrate data
  • Site visits and field observations
  • Professional judgment

We follow our Quality Assurance Program Plan (QAPP) for monitoring, sampling, and sample handling, which aligns with EPA’s standard practices for environmental data collection. The Utah Public Health Laboratory analyzes our samples using its standard methods. Learn more about our Quality Assurance & Quality Control Program.

We store our water quality data in Utah’s water quality data systems and share them with EPA’s national databases, where the public can download and analyze the data.