Water Source and Distribution in Thurston County
The public water system serving Thurston County, including the area around Lacey, draws water from groundwater sources. This water is treated and then distributed via a widespread network reaching thousands of local households, with over 34,000 connections. Understanding the characteristics of this groundwater supply aids residents in grasping what is known from area-wide testing before deciding on any water treatment options.
Why the Reporting Level for 1,2,3-Trichloropropane Is Extremely Low
The sensitivity of testing
1,2,3-TCP is measured using methods capable of detecting very small concentrations, as low as 0.03 micrograms per liter (or parts per billion). This low reporting level is set because 1,2,3-trichloropropane is a synthetic chlorinated solvent with potential health concerns at very low exposure levels. This differs greatly from common metals, which are typically measured at much higher thresholds.
The role of federal monitoring
The EPA’s Unregulated Contaminant Monitoring Rule (UCMR3) measured 1,2,3-TCP in the Lacey Water Department system multiple times between 2014 and 2015. No detections above 0.03 micrograms per liter were recorded, reflecting the absence of detectable concentrations at or above the reporting threshold in these samples.
Why 1,2,3-Trichloropropane Resists Air Stripping and Treatment Implications
Characteristics of TCP in water treatment
1,2,3-TCP is resistant to removal by air stripping because it has a low volatility relative to other contaminants. This resistance means that treatment methods relying solely on air stripping are ineffective for reducing TCP levels.
Choosing appropriate equipment classes
Given the chemical properties of 1,2,3-trichloropropane, households assessing treatment options should consider equipment technologies that specifically address chlorinated solvents by adsorption or filtration processes rather than relying on aeration methods.
How Seasonal or Multi-Year Variation Is Reflected in Thurston County Records
Sampling timeline and frequency
The monitoring data for the Lacey Water Department includes 26 samples collected over approximately seven months from December 2014 through June 2015. These multiple measurements help provide a snapshot of variation during this period.
Consistency of results
All samples showed no detection above the reporting threshold, indicating stable, low levels of 1,2,3-TCP during this time. Longer-term or seasonal changes beyond this timeframe would require additional testing to assess.
Considerations for Different Household Types
Larger households and extended water use
Households with higher water demand may need to ensure that treatment equipment can handle increased flow rates or volume without loss of efficiency.
Seasonal or secondary properties
Properties used intermittently or seasonally might require different treatment considerations, such as equipment capable of maintaining effectiveness during periods of stagnation or less frequent use.
Differences Between Public-System Records and Private-Well Testing
Scope of public system data
The EPA data cited pertains to a large public water system serving over 100,000 people and represents an aggregate water quality profile, not individual household water supplies.
Importance of individual testing
Because private wells or individual home plumbing can have different water quality characteristics, a private water test is essential to establish a home's specific 1,2,3-TCP concentration before selecting treatment equipment.
What Not to Conclude From Area-Wide Data
Absence of detection is not a guarantee
The fact that no 1,2,3-TCP was detected above 0.03 micrograms per liter in the public water system samples does not confirm that every well or tap in the area is free of this chlorinated solvent.
Regulatory context
The public water system in Thurston County has no health-based violations on record related to 1,2,3-trichloropropane, and no federal maximum contaminant level (MCL) currently exists for this compound. This indicates regulatory monitoring rather than any finding of unsafe water.
Guidance for households
Households should perform specific water testing to determine their own water’s 1,2,3-TCP content. If treatment is chosen, equipment like the Autotrol 1,2,3-TCP Filter—designed for chlorinated solvents—ships ready to configure for residential use and aligns with treatment needs that typical aeration methods do not meet.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2015-06-30. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for Lacey Water Department (WA5343500), WA: 26 results across 1 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level