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Water Blog

Algal Blooms Can Affect Water Quality, but It’s Safe to Drink

Summer’s warmer temperatures provide an excellent breeding ground for algal blooms in source water reservoirs. The molecules from these algal blooms can release a swampy or earthy taste and odor into the water. Despite the undesirable taste and odor, the water is still safe to drink. 

Greeley staff strives to detect algal blooms early by conducting weekly tests during peak algal bloom months and monitoring source water conditions for early indicators of algal growth. The city uses an aeration system near the Boyd Lake water intake to encourage water circulation and oxygenation, which reduces the release of nutrients from the lake sediment into the water column.  Reducing the amount of nutrients in the water and promoting water circulation limits algae growth and can lessen the frequency and scale of algal blooms. 

Michaela Jackson is the Water Quality and Regulatory Compliance Manager for the City of Greeley. Her team knows where algal blooms thrive so they can stay one step ahead. 

“We know where algal blooms are most likely to occur in our source water system due to water quality monitoring, operations, and hydrology,” she said. “Algae can enter a phase of excessive growth if they receive sufficient nutrients. Runoff from wildfire burn scars can contribute additional nutrients to the source water, which supports larger and more frequent blooms.” 

However, due to the dynamic nature of algal blooms, we aren’t always able to catch these compounds before they enter distribution system. Once that happens, customers may detect an earthy taste or odor in their tap water. They should call the Water Taste and Odor hotline at 970-336-4097 or send an email to

Greeley staff responds immediately to reports of undesired tastes and odors in Greeley’s water. Greeley’s two water treatment plants at Bellvue and Boyd Lake add powdered activated carbon to remove undesirable taste and odor compounds from the water during treatment.  

The water quality team appreciates customer feedback on undesirable tastes and odors in the water because it helps staff track how long it takes to remove compounds from the system. 

“When water demand is high and the concentrations of these compounds are low, they can be gone in a few days,” Jackson said, “When concentrations are higher, however, it can sometimes take a week for the taste and odor to clear out from the distribution system.” 

Customers can lessen the taste and odor of their water: 

  • Refrigerate the water. Taste and odors start to go away as water cools. 

  • Add some lemon to counteract the undesirable taste or odor. 

  • Water filters that use activated charcoal can remove the undesirable taste and odor. 

  • It’s important to remember that the water is safe to drink.

Customers may also occasionally encounter other tastes and odors like metal, chlorine, or rotten eggs in their water. These are not normally associated with algal blooms. Customers should notify the water quality team at 970-336-4097 or

Contact Us

Greeley Water and Sewer

1001 11th Ave, 2nd Floor
Greeley, CO 80631

Monday - Friday 8am - 5pm

970-350-9811 tel
970-350-9805 fax

Water Conservation

970-336-4168 for Water Budget


Water 7am-3pm 970-350-9320
Sewer 7am-3pm 970-350-9322
after hours970-616-6260

Other Numbers

billing970-350-9811 (dial 2 for billing clerk)
start or stop service970-350-9811 (dial 2 for billing clerk)
water taste or odor970-350-9836
water pressure970-350-9320
water restrictions & violations970-336-4134
utility line locates811
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