As a groundwater geologist, I can tell you Trichloroethylene (TCE) is bad stuff. TCE has unique molecular properties; it literally sticks to the inter-stitial porosity of the rock. It will take millions of dollars and probably decades, if not centuries, to fully clean up a TCE site.
In fact no large TCE contamination site has been fully remediated. The clean-up for one of the largest TCE sites (Aerojet near Sacramento) is scheduled by EPA to last between 300-400 years at a cost so far of over a hundred million dollars. (Don't worry large defense contractors get reimbursed by DOD for about 90% of their clean-up costs! If you're a defense contractor, the principle "the polluter pays" doesn't apply.)
Also, I'd be very skeptical of filters making drinking water safe; the tolerance for TCE is in the parts per billion. Filters can fail easily. Just a small amount of TCE over time can cause problems like leukemia and other cancers.
The contamination plume is probably spreading (every time it rains) so it must be monitored closely to make sure additional drinking water supplies are not contaminated.
Unfortunately, we're still discovering many contaminated sites all over the U.S., 25 years after the Love Canal disaster forced congressional passage of the Superfund program.

I appreciate Shen. Dem's comments w/good info on TCE. Most folks eyes glaze over when they read about chemicals/chemistry, "parts per million" (ppm), and dosage exposures in toxicity reports. The bottom line is TCE is bad stuff that should not be in a land fill. It can/does leach out and make its way into ground water.

TCE is a solvent commonly used to clean grease off machinery and it is also used in Dry Cleaning (perchloroethylene- PERC)There has been a trend for Dry Cleaners to adopt environmentally friendly drycleaning methods but PERC is still prevalent.

A wiki overview on TCE/PERC, including health impacts is here

The book and movie "Civil Action" is about PERC contamination.

If you've seen the movie "A Civil Action" you'll recall one of the lawyers couldn't even pronounce trichloroethylene. PERC contamination is mostly the result of dry cleaners dumping their used wastes improperly. Over time PERC breaks down chemically to TCE, which is why you often find both at the same contamination site. For example, two dry cleaners up in Belmar NJ dumped PERC into their septic systems for years, and now there's a 3 mile contamination plume extending all the way to the ocean with hundreds of homes effected. It will take decades and millions of dollars to remediate. Another problem with TCE is it's heavier than water so it sinks to the bottom of the groundwater table, making it even harder to remove.