Managing 1,2,3-TCP in Kent County: What Dover Households Should Know About Local Water Quality

This week, Dover-area homeowners face a choice about whether to act on concerns regarding 1,2,3-trichloropropane (TCP) in their water supply. Understanding government monitoring results, how the contaminant arrives, and evaluating treatment capacity can help decide next steps.

If you consider granular activated carbon contact time, why bed depth matters more for TCP than for taste

Granular activated carbon is a common way to address chlorinated solvents like TCP in water. For this compound, the depth of the carbon bed is more critical than for removing taste or odor issues. A deeper carbon bed increases contact time, allowing more effective interaction between TCP molecules and the carbon surface. This is important because 1,2,3-trichloropropane adsorbs more slowly than substances responsible for taste concerns. If a device has insufficient bed depth, it might not adequately reduce TCP even if taste improvement is noticed.

If you observe the agricultural land-use history of the region and how it maps onto detections

The Dover Water Department's groundwater source sits under an area with a history of agricultural activities dating back to the mid-20th century. TCP was used as a soil fumigant impurity in the 1950s through the 1980s, which has allowed residues to migrate into groundwater over decades. This legacy use explains why 1,2,3-TCP is monitored in this area. However, historical land use does not indicate ongoing presence in every water source or household tap. It provides context for sampling efforts rather than a definitive statement about any home’s water.

If you examine how the constituent enters groundwater or the distribution system in this region

1,2,3-Trichloropropane enters groundwater primarily through past agricultural chemical applications that seeped into the soil and percolated downward. Because this chlorinated solvent is persistent in soil and water, it can remain in aquifers for long periods. From groundwater, TCP may enter municipal well sources supplying the Dover system. Distribution system presence reflects source water quality but can also be affected by treatment steps and infrastructure conditions.

If you understand how public-system records differ from private-well testing in what they establish

The US EPA’s sampling record for the Dover Water Department reflects system-wide monitoring conducted between 2013 and 2015, covering 28 samples with zero detections above the reporting level of 0.03 micrograms per liter (µg/L), or parts per billion. This record applies to the public water system as a whole and does not represent testing of individual household taps or private wells. To determine TCP levels at a specific residence, separate testing of that household’s tap water is necessary. Public system records provide a regional overview rather than precise household conditions.

If you want clarity on what ‘detected,’ ‘median,’ and ‘range’ mean in the sampling record on this page

In the EPA’s Unregulated Contaminant Monitoring Rule results, 'detected' means the instrument measured the chemical at or above a defined reporting level—in this case, 0.03 µg/L for TCP. A 'median' would represent the middle value in a data set, but since no results exceeded the reporting level, no median TCP concentration above that threshold is reported for Dover. The 'range' indicates the span of detected concentrations but here implies all results were below this threshold. Importantly, a detection does not equate to a regulation breach or health risk; it is a measurement used to assess water quality trends.

If you need to judge treatment capacity against your household's or facility's daily demand

Choosing treatment to address TCP involves ensuring the technology can handle the volume of water your home uses daily. Treatment devices designed to reduce 1,2,3-trichloropropane commonly rely on granular activated carbon configured for adequate contact time and bed depth. Considering your household's typical water consumption and peak demand helps select a solution dimensioned to maintain effectiveness without frequent regeneration or media replacement. The Fleck 1,2,3-TCP Filter ships ready to configure for residential flows and is documented to address this contaminant effectively when sized properly.

This information draws from the EPA's public water system record for the Dover Water Department serving Kent County, Delaware. For more details, refer directly to official EPA sources on Unregulated Contaminant Monitoring Rule data.

Where this information comes from

Source: EPA SDWIS public water system record. Sampled 2015-03-12. These figures describe the public water system's record, not the plumbing inside any individual building.

On record: EPA UCMR3 monitoring (2013-2015) for Dover Water Department (DE0000571), DE: 28 results across 1 listed contaminants, 0 detections above the reporting level; nothing detected above the method reporting level