Every residential pool in Colorado loses water to evaporation. The dry Front Range air and the intense summer sun at Longmont's 4,979-foot elevation produce higher evaporation rates than pools in more humid climates experience. The question that trips up Longmont pool owners every summer is whether the water loss they are seeing is within normal evaporation range or indicates a leak in the pool structure, plumbing, or liner.
How Much Evaporation Is Normal in Longmont?
A residential pool in Longmont's climate can lose between a quarter inch and half an inch of water per day through evaporation alone under summer conditions: high UV exposure, low relative humidity, and afternoon temperatures in the upper 80s and 90s. Over a week, that adds up to 1.75 to 3.5 inches of evaporation, which is a significant volume. A pool owner who notices a 2-inch drop over a week and immediately suspects a leak may actually be looking at normal evaporation. A pool owner who sees a 4-inch drop in the same week is more likely looking at evaporation plus a leak.
The Bucket Test: The First Step
The bucket test is the standard method for distinguishing evaporation from a pool leak without any equipment. Fill a five-gallon bucket with pool water to the same temperature as the pool. Place the bucket on a pool step so it sits at water level, with the bucket rim just above the pool surface. Mark the water level inside the bucket and the pool water level on the outside of the bucket. Run the pool pump on its normal schedule. After 24 hours, compare the two levels.
If the pool has dropped more than the bucket, the pool is losing water faster than evaporation accounts for, and a leak is present. If the pool and bucket have dropped the same amount, the loss is evaporation only. If the pool has dropped significantly more than the bucket with the pump running, but nearly the same as the bucket with the pump off, the leak is in the recirculation plumbing rather than the pool structure itself.
Where Pool Leaks Occur in Colorado Homes
Colorado's Zone 5b freeze-thaw climate is the primary driver of pool structure and plumbing leaks. Pools in Eagle Crest and other Longmont neighborhoods where in-ground pools were installed in the late 1990s and early 2000s are now twenty to twenty-five years old, and the polyethylene return and supply plumbing in those systems has been through twenty-five seasons of freezing and thawing. Micro-cracks in the fittings and pipe connections near the pool deck edge are the most common leak source. Liner failures at the main drain, the return fittings, and at any penetration through the pool shell are the second most common category.
Pool leak detection uses pressure testing on the circulation plumbing, dye testing at fittings and penetrations, and acoustic detection for buried supply line failures to locate the specific failure point before any excavation or liner repair is attempted. Call (303) 552-3896 to schedule pool leak detection in Longmont.