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Millcreek Journal

Good news for Mill Creek six months after concrete spill

Mar 07, 2022 01:01PM ● By Deb Hafner


esidents of Millcreek, concerned about the health of their namesake creek after a massive concrete spill last summer, can rest assured that the creek water is safe and fish have been repopulated.  

On a bright day in February, while kids and parents fed the ducks hanging out at the pond in Scott Avenue Park, there was no evidence that a massive amount of concrete had polluted stream waters here last summer. 

Ducks and geese spend winter resting on the banks of the pond at the 6-acre Scott Avenue Park.  They hang out on the man-made overflow basin in the northeast corner of the park that was once part of a trout hatchery in the 1970s.   

The overflow basin at Scott Avenue Park is fed by Mill Creek and maintained by Salt Lake County. Mill Creek is 18.5 miles long and originates in the Wasatch Range. It flows west and converges with the north-flowing Jordan River, where they eventually feed into the Great Salt Lake.

On its westward journey, Mill Creek winds through almost all of the city of Millcreek—under highways, through people’s backyards, along trails and in and out of parks like the Scott Avenue Park. 

Millcreek Mayor Jeff Silvestrini said, “The creek is an identifying part of our city. It is our signature creek and namesake.” 

Last July, about 300 dead fish, which Silvestrini said were hard to look at, floated down the creek as far west as 500 East, the upsetting results of a concrete spill that happened on July 29, 2021, on the west side of I-215 at a construction project. 

The spill was caused when concrete waste from UDOT construction contractor, Ralph L. Wadsworth Construction, was dumped into a storm drain that they thought was no longer in use. The outflows were not blocked, and the concrete was discharged into the creek. 

Filling a storm drain vault with concrete is an acceptable practice at large construction sites if the drain is abandoned or no longer in use. This particular storm drain system, however, had not been sealed. 

Cement contains a large amount of alkali, and when it hit the water, it instantly raised pH levels to a dangerous high, killing trout and other fish in the vicinity. See

Myriad environmental agencies were alerted and rapidly mobilized—the Utah Department of Environmental Quality (DEQ), the Utah Division of Wildlife Resources (DWR), the Utah Division of Water Quality (DWQ), Millcreek City, the Salt Lake County Health Department, and UDOT—launching into a massive cross-agency coordinated cleanup to retrieve and remove concrete from the water and banks of the creek.  

In addition, within two hours of learning of the incident, Ralph L.Wadsworth Construction hired environmental cleanup firm, Clean Harbors, who was onsite and working on cleanup efforts within one hour of being retained. 

The Salt Lake County Health Department issued a warning for people and domestic animals to steer clear of the stream and dispatched workers door-to-door notifying Millcreek residents of the unsafe water. 

Faith Heaton Jolley, the spokesperson for the DWR, said the fish population that was affected was primarily composed of Bonneville cutthroat trout, brown trout and the occasional tiger trout. Approximately 300 dead fish were collected from the impacted area, but that number likely represents only a portion of the population that was impacted by the spill, said Jolley. Previous surveys suggest population estimates of 600 fish per mile in the area that was impacted by the spill. 

Over 60 bags of concrete were cleaned up and hauled out of the creek and riparian zones. A heavy rainfall the weekend after the spill flushed the water downstream, and the creek was deemed safe by the environmental agencies.  

Now, six months later, there is good news for residents who are wondering about follow-up, how the creek can be protected going forward, and if they will be able to fish this spring.

John Gleason, UDOT spokesperson, stated that “for the duration of the project, UDOT and RLWadsworth will discuss the proximity (within 50 feet) and potential of work that could impact any waterways at all construction pre-activity meetings. Additionally, work will stop at defined stages to ensure work is proceeding without risk to the stream and according to the contract before proceeding to the next stage.”

The DWQ issued a notice of violation to UDOT and Ralph L. Wadsworth Construction in October of last year, and according to Gleason, “RLWadsworth is committed to support restoration efforts.”

Last October and November the DWR began restocking Mill Creek with trout—12,500 to be exact. 

The DWR stocked Mill Creek with the following: 5,000 2- to 3-inch Bonneville cutthroat trout between Thousand Springs and the mouth of Mill Creek Canyon; 2,000 2- to 3-inch Bonneville cutthroat trout in four locations of Mill Creek between 1900 East and 3400 East; and 5,500 2- to 3-inch Bonneville cutthroat trout at the Winter Gate or Maple Grove area. 

Some of the fish stocking was already planned, according to Jolley, but they increased the number of fish and altered the locations of the stocking in response to the fish that were killed in the cement spill. 

Jolley said DWR has plans to stock an additional 5,000 fingerling Bonneville cutthroat trout within the impacted area over the next three years. Additional larger fish may also be stocked if they are available this year and in 2023. Additional or future stocking updates can be found on the DWR website:

Mike Slater, Sportfish Project leader with the DWR, said there are no concerns for people fishing in the impacted reach of Mill Creek, but most fish will be small this year, probably reaching 6 inches by the end of the summer.  

As to the quality of the water in the creek and the riparian zones, testing continued throughout the summer, and there were no reported concerns with water quality or environmental hazards. 

The silver lining in the wake of the unfortunate accident is the demonstration of cross-agency coordination and the glimpse into the fluidness with which the state-wide agencies can mobilize the public rarely sees.  

The Division of Water Quality Director, Erica Gaddis, noted “We are appreciative of the collaborative efforts of the City of Millcreek, UDOT, Clean Harbors, and the Division of Wildlife Resources to work in partnership with our agency and ensure that the environmental impact of this spill was quickly understood and addressed. This level of coordination and responsiveness minimizes risk to public health and the environment, and is what the public should expect from both public and private organizations.”

Silvestrini was pleased with the way the agencies came together to repair the damage done to the beloved city creek. “From the time this spill was discovered by a Millcreek inspector who alerted the appropriate entities, Millcreek was pleased by the response and communication between all parties,” he said. “This spill impacted several Millcreek residents along the stream and the fish kill was very difficult to observe. I feel the clean-up efforts were well done and with the added benefit of two major rain storms, the impacted properties were restored and the fish population has been restocked to bring Mill Creek back to a good condition.” λ