Longmont Water Softeners & Water Treatment

About Longmont Water

Longmont's water supply is managed by Longmont Water, drawing primarily from Union Reservoir and the St. Vrain Creek watershed — both fed by mountain runoff from the Front Range. During peak demand or drought conditions, the district supplements with purchased Denver Water supply.

At 6.8 GPG, Longmont's water sits in the moderate-to-hard range — below the Denver metro average of 7.8 GPG. The mountain runoff origins mean less mineral contact time compared to groundwater-heavy cities like Brighton. However, 6.8 GPG is still sufficient to cause scale buildup over years and reduce soap lathering efficiency.

During periods when Denver Water supplemental supply increases (typically late summer drought periods), Longmont's hardness can temporarily rise to 7.5–8 GPG. A modest treatment system handles this range comfortably.

Recommended Treatment for Longmont

At 6.8 GPG, Longmont homeowners have flexible treatment options. A 24,000–32,000 grain salt-based water softener is fully adequate for most households and will be right-sized for efficient, cost-effective operation at this hardness level.

A salt-free template-assisted crystallization conditioner is also a practical choice at 6.8 GPG. These systems are generally effective below 7 GPG and offer zero maintenance, no salt costs, and no water waste from regeneration cycles — making them particularly appealing to environmentally conscious Longmont homeowners.

Some Longmont homeowners choose to forgo softening entirely and install only a whole-house activated carbon filter to address chloramine taste and odor. At 6.8 GPG, this is a defensible strategy for households with newer plumbing and modern, scale-resistant appliances — though a softener remains the better long-term value.

Frequently Asked Questions