Distinguishing Lead from Iron and Hardness Concerns
In King County residential water, lead is distinct from more commonly confused issues like iron staining or water hardness. Unlike iron, which often colors water and creates residue, or hardness minerals that cause scale buildup, lead presence originates mainly from plumbing materials leaching into water after it leaves the source. This makes lead a concern primarily related to the internal plumbing environment rather than the raw source itself.
What Changes at Your Tap with Treated Water
When water treatment technology like the Fleck Lead in Water Filter is active, water that previously carried trace amounts of lead downstream from pipes is filtered to reduce lead content at the point of use. The treated water typically shows improved clarity, no metallic taste, and a reduced chance of lead exposure from drinking, cooking, or bathing. This filtering effect occurs without altering the water’s natural mineral balance or requiring chemical additives.
Lead's Pathway into Groundwater and the Distribution System
King County’s Auburn City public water system relies on groundwater sources. Lead is not naturally occurring in the region’s groundwater in significant amounts but can enter the distribution system through corrosion of lead-containing plumbing components such as older pipes, fixtures, or solder. The EPA’s monitoring focuses on the water at customer taps, reflecting lead levels influenced primarily by plumbing materials rather than the groundwater source itself.
Reading the EPA Lead Sampling Record: A Homeowner’s Example
The most recent EPA data for the Auburn City system shows a 90th percentile lead concentration of 0.0022 mg/L from samples collected at customer taps. This measure means that 90% of the tested taps had lead levels at or below this value, which is well below EPA action levels. It reflects lead presence in plumbing rather than the water source and does not indicate a violation or unsafe water in this system. For context, this data stems from samples representing many homes and does not specify the condition in any individual residence.
Understanding Laboratory Testing for Lead in Household Water
A certified laboratory test for lead includes sampling water directly from your home tap, usually after a period of stagnation, to capture lead leached from household plumbing. The laboratory will report lead concentration in milligrams per liter (mg/L), allowing comparison against EPA action levels. Testing at this scale is the only way to determine your household’s precise lead concentration because system-level records cannot substitute for individual sampling.
The Role of Sample Depth and Source in Expected Lead Levels
Sample collection depth and source type affect expected lead measurements. In King County, wells drawing groundwater reduce the direct natural lead risk, but older internal plumbing may increase lead levels at shallow sampling points like kitchen faucets. Deeper samples taken closer to the groundwater source typically show negligible lead. This highlights the importance of sampling at points of use within the home to assess potential lead exposure accurately.
Recommended Test and Action
To establish your household's current lead levels, order a certified laboratory lead test of water collected after typical stagnation at your kitchen tap. This test provides a direct measurement of any lead introduced by your internal plumbing. Should the results warrant, using a Fleck Lead in Water Filter can effectively reduce lead exposure by filtering water at the point of consumption, providing an added layer of safety and peace of mind for your family.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2024-12-31. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA SDWIS record for Auburn City of (WA5303350), groundwater supply, serving 107655 people: 0 health-based violations of 2 total; lead 90th percentile 0.0022 mg/L