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Updates -
Tibble Fork Reservoir Sediment Release August 2016

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Update: May 30, 2017

Update: March 30, 2017

The Division of Water Quality (DWQ) is seeking over $145,000 in penalties and reimbursements from the North Utah County Water Conservancy District (NUCWCD) for the release of metal-laden sediment from Tibble Fork Dam into the American Fork River on August 22, 2016.

Under the Settlement Agreement, NUCWCD has agreed to the following:

  • $52,500 civil penalty
  • $92,633.55 for reimbursement to DWQ, primarily for sampling and monitoring costs incurred by DWQ from August 23 to September 5, 2016

The District also agreed to a monitoring plan and remediation plan for the river to pre-spill conditions based on recorded conditions above the Tibble Fork Dam on the North Fork of the American Fork River.

The settlement addresses requirements outlined in the Notice of Violation and Compliance Order issued to NUCWCD on September 28, 2016, for discharging pollutants, degrading water quality beyond state standards, and failing to notify DEQ. The penalty is set under state statute and based on the incident’s impact on public health and the environment.

The public has a chance to comment on this agreement during a 30-day period that runs from March 31 to May 1, 2017. Comments can be sent to Kevin Okleberry at kokleberry@utah.gov or P.O. Box 144870, Salt Lake City, Utah 84114-4870. Comments must be received before 5 p.m. on May 1, 2017.


Update: October 31, 2016

The North Utah County Water Conservancy District (NUCWCD) filed a Request for Agency Action before the Department of Environmental Quality to ask for a review of the Notice of Violation/Compliance Order (NOV/CO) issued by DEQ on September 28, 2016.

The NUCWCD asks that the NOV/CO be modified to account for facts it provides in the Request and actions it took to remedy environmental issues associated with the Tibble Fork Reservoir drainage and sediment release.


Update: September 27, 2016

The Division of Water Quality (DWQ) issued a Notice of Violation and Compliance Order (NOV/CO) today to the North Utah County Water Conservancy District (NUCWCD) for the August 20, 2016, sediment release from Tibble Fork Dam.

Violations include:

  1. Discharging that is not authorized under an existing,valid state discharge permit (Utah Pollutant Discharge Elimination System permit, or UPDES).
  2. Releasing a pollutant into a water of the state which constitutes a menace to public health and welfare, is harmful to wildlife, fish, or aquatic life, or impairs domestic, agricultural, industrial, recreational, or other beneficial uses of the water
  3. Violating the state's antidegradation policy for Category 1 waters by degrading the water quality in a manner that interferes with or harms existing in-stream uses.
  4. Discharging wastes or other substances in a manner that may interfere with a water's designated beneficial uses or violate applicable water quality standards. 
  5. Discharging a waste that is offensive (e.g. debris) or causes conditions that produce undesirable effects for aquatic life, fish, or human health.
  6. Discharging a waste that degraded water quality in American Fork River beyond the state water quality standards set forth in the Utah 401 Water Quality Certification issued to the U.S. Army Corps of Engineers 404 permit. Specifically, failure to conduct activities in the water of the state that:
    • Minimize turbidity increases to less that 10 nepholometric turbidity units (NTUs) numeric criteria for the assigned beneficial use class 2B and 3A in the American Fork River.
    • Immediately modify the implemented best management practices (BMPs) to ensure compliance with water quality standards.
    • Violate other 401 Cert conditions as enumerated in the NOV/CO

The NOV also cited the NUCWCD for failure to meet Army Corps of Engineers and DWQ permit conditions and failure to report the incident to DWQ immediately.

Conditions that the NUCWCD must meet under the Compliance Order (CO) include:

  • The initiation of all actions necessary to come into compliance with state water-quality laws and rules
  • An explanation as to why a sediment release mitigation plan was not implemented at the time of the release
  • An explanation of the reasons behind the failure to notify federal, state, or local agencies immediately after the sediment release
  • A comprehensive description of the cleanup plan for the American Fork River drainage, including how the polluted sediment will be removed and the steps that will be taken to protect public health and rehabilitate wildlife habitat in the river
  • Preparation of a comprehensive monitoring plan that will demonstrate that 1) the sediments in the river are not harmful to public health, aquatic life, and irrigation/secondary water and 2) the restoration efforts are effective

NUCWCD has thirty days to respond to the NOV and file a request for agency action. A request for agency action initiates an administrative review process which may include informal discussions to negotiate a settlement or the appointment of an administrative law judge to conduct an adjudicative proceeding.


Update: September 12, 2016

Results from samples collected September 3,5, and 6, 2016, for turbidity and total suspended solids (TSS) show the river downstream from Tibble Fork Dam recovering to the point that dam operators are no longer in violation of turbidity and TSS standards.

The latest sediment data from the samples taken by the Park Service are consistent with Division of Water Quality samples.



Update: September 8, 2016

The Division of Water Quality (DWQ) continues to monitor conditions in the American Fork River with the assistance of the National Park Service, the U.S. Forest Service, and the Utah County Health Department (UCHD).

The construction contractor has completed the bypass channel designed to prevent the contaminated sediments in the reservoir from eroding into the river. The North Fork of the American Fork River is now flowing through this channel. Water quality in the river has improved noticeably since then the completion of the bypass channel, with the bottom of the creek becoming visible again in most locations.

Sampling Results

Water samples have been taken at least every other day from all locations on the river since the sediment release.

The latest samples were analyzed for total suspended solids (TSS), a measurement of solid material suspended (not dissolved) in the water, and turbidity, a measure of water clarity. The analysis showed the suspended solids in the river dropped to their lowest levels on September 1, 2016. While the turbidity of the water continues to show overall improvement, it fluctuates from day to day. Samples taken over the Labor Day weekend are currently being analyzed, and data will be available before the weekend.

Concentrations of total metals in the water column in samples collected August 23, 2016, through August 30, 2016, below Tibble Fork Reservoir do not exceed human health screening values for recreational exposure. Concentrations of dissolved metals in the water column in samples collected August 23, 2016, through August 30, 2016, do not exceed screening values for agricultural or aquatic-life use.

The UCHD collected samples from Highland Glen Reservoir, Heritage Park, and Manila Reservoir on August 31, 2016, in response to concerns about the quality of irrigation water used downstream. Analysis of total and dissolved metals concentrations in samples taken at these locations confirmed that metals levels in the water do not exceed the EPA screening values for recreational, agricultural, or aquatic-life uses.


Update: August 27, 2016

The Division of Water Quality has analyzed data from samples that were collected below Tibble Fork Reservoir on August 24, 2016. Metals concentrations are very similar to those collected on August 23, 2016.

None of the metals data exceed Utah's water quality standards. The turbidity in the river appears to have improved, but the sediment in the water measured on Wednesday continued to exceed Utah's narrative and numeric water quality standards.

The Division of Water Quality, in partnership with the U.S. Forest Service (USFS), collected water quality and sediment samples today. Data will be reported to the public as soon as it is available. The creek level was significantly lower today compared to yesterday, and the water-quality sonde (measurement device) installed yesterday had to be moved to a deeper area of the river.


Update: August 26, 2016

News Release: DEQ Water Samples Show Metals Contamination in American Fork River Public Cautioned to Avoid Sediments (pdf)

The Division of Water Quality (DWQ) was notified on August 23, 2016, of a large release of sediment from Tibble Fork Reservoir into the North Fork American Fork River. DWQ collected water and sediment samples on August 23, 2016, to determine the water-quality impacts from the release. DWQ analyzed the water chemistry and sediment samples for a broad range of heavy metals and screened the findings against recreational, agricultural, and aquatic-life criteria.

Advisories and Use Determinations

Based on DWQ data analyses, state and local officials have made the following use determinations and issued the following advisories:

  • The Utah County Health Department (UCHD) is posting “CAUTION” signs along the American Fork River urging the public, and especially children, to avoid wading in the river or playing on the banks. UCHD also advises people exposed to riverbank sediment to wash it off their skin, clothing, or equipment to avoid possible contamination of vehicles or homes.
  • Springs used by American Fork residents for drinking water are not connected to the impacted areas. American Fork City is testing the springs as a precaution. At this time, there is no indication that any culinary water has been impacted.
  • The Utah Department of Agriculture and Food (UDAF) does not believe the water poses a risk for livestock or crop irrigation.
  • The Utah Division of Wildlife Resources (DWR) is urging anglers to practice “catch and release” as a precaution. DWR biologists are collecting fish from the river to monitor potential impacts and ensure that fish are safe to consume.

Sampling Schedule

Division of Water Quality (DWQ) scientists have been sampling the river daily since August 23, 2016, and will continue to sample throughout the weekend. DWQ is also deploying sondes (measuring instruments) above and below the reservoir to monitor the water quality continuously and document any changes in temperature, turbidity, pH, and other criteria.

Dam Rehabilitation Project Update

The dam owners, along with the consulting engineers and contractor, are currently installing a canal that bypasses the contaminated sediment in the lakebed. This project is progressing quickly and should be in place by the weekend. When completed, it is expected this will significantly reduce if not eliminate the discharge of potentially contaminated sediments from the lakebed. The dam restoration project itself is expected to be completed December 2016.

Data Summary

Water and sediment samples were collected on August 23, 2016, at four locations:

  1. American Fork River at the mouth of the canyon
  2. North Fork American Fork River above the confluence with the South Fork American Fork River
  3. North Fork American Fork River below Tibble Fork Reservoir
  4. North Fork American Fork River above Tibble Fork Reservoir


(Click for large view)


(Click for large view)

DWQ data analyses from water and sediment samples from these locations, along with data taken by the National Park Service at Timpanogos National Monument the previous day, revealed the following:

  • Dissolved and total metal concentrations in water quality samples collected on August 23, 2016, below Tibble Fork Reservoir are two to 10 times higher than the concentrations of metals above Tibble Fork Reservoir.
  • Total metal concentrations collected below the reservoir on Monday, August 22, 2016, are significantly higher than the samples collected by DWQ on Tuesday, August 23, 2016. This suggest that the DWQ samples are not representative of the worst conditions in the river that occurred between August 20, 2016, and August 22, 2016.
  • Measurements of water clarity (turbidity and total suspended solids (TSS)) indicate clear violations of Utah’s narrative and numeric water quality standards.
  • Concentrations of dissolved in water quality samples collected above and below Tibble Fork Reservoir on August 22, 2016, do not violate Utah’s water quality standards for aquatic life or agricultural uses.
  • Concentrations of total metals in the water column collected on August 22, 2016, and August 23,2016, below Tibble Fork Reservoir do not exceed human health screening values for recreational exposures.
  • Sediment metal concentrations collected below Tibble Fork Reservoir exceed human health screening values for lead and exceed aquatic life screening values for arsenic, cadmium, copper, lead, manganese, nickel, and zinc.
  • Sediment metal concentrations collected above Tibble Fork Reservoir on August 23, 2016, also exceed freshwater aquatic life screening values for arsenic, cadmium, lead, manganese, and zinc. The magnitude of these exceedances are not as pronounced as the data for samples collected below the reservoir.