HAYWARD (CBS) -- Contaminated well water, cockroach infestations: Horror stories from tenants abound concerning one of the Bay Area's most notorious landlords. Tenants told us they felt helpless against Richard Thomas. But as a result of a CBS5 investigation earlier this year some have gotten relief.

Katrina Rodriguez brought the foul smelling situation to our attention: A group of homes smack dab in the middle of Hayward bathing in and even drinking water from a well.

We tested the water and found it contaminated with coliform bacteria

But landlord Richard Thomas, who owns hundreds of rental units in the bay area, didn't want to talk about it.

Thomas could have hooked up to city water years ago. The line runs right under the street in front of the property. But staying off the water grid means no bills. Until we got involved, there was no oversight.

County health inspector Ron Torres admits it did help that we brought the situation to his agency's attention. The Alameda County Department of Environmental Health has jurisdiction over wells that serve 5 to 14 families, like the one in Hayward. But he admits it's been a low priority.

"We have had them under some monitoring in years past but they have since fallen off the map here," Torres told CBS5.

That allowed Thomas to treat the well the cheap way, with Clorox. As a result of our investigation the county forced Thomas to install a professional chlorination system and he is required to submit monthly bacteriological samples to the County.

Health inspectors are now checking other wells. "We need to update our ordinance to better monitor these kinds of systems, so they are not slipping through the cracks," Torres said.

Read previous stories:

Part 1: Hayward Landlord Accused Of Providing Tainted Water

Part 2: Ex-Tenant: Bay Area Landlord Didn't Fix Roach Problem