The Mobile Area Water and Sewer System serves roughly 279,000 people — the largest system in either county by a wide margin. Here is what the federal record and the independent testing data actually show, without either reassurance or alarm attached.
The compliance record
MAWSS carries 25 violation records with the EPA, spanning 2020 to 2025. One is health-based.
That distinction is doing a lot of work. The other 24 are monitoring and reporting — a required sample or report filed late. Both appear in the same database under the same word, and quoting the total without the split is how a diligent utility with imperfect paperwork gets described as having a water-quality problem.
For context, across all 15 systems serving these two counties there are 819 violation records and two are health-based.
What is detected
Twelve substances are found above the Environmental Working Group's health guidelines. Every one is within its legal limit where a legal limit exists.
The pattern is unmistakable — disinfection by-products dominate: trihalomethanes, haloacetic acids in two groupings, chloroform, bromodichloromethane, dibromochloromethane, and chlorite.
That is a surface-water signature. MAWSS draws from a reservoir, reservoir water carries organic matter, and disinfectant reacting with organic matter produces by-products. Warm climate accelerates it. It is the cost of water that does not carry bacteria, and the trade is not close.
Also present: chromium (hexavalent), and radium, which shows up in every single system in both counties because it is naturally occurring in the geology rather than anything anyone did.
The four with no legal limit
Four of the twelve — chloroform, bromodichloromethane, dibromochloromethane, and hexavalent chromium — are listed against no legal limit.
This is worth understanding properly. It does not mean they are harmless, and it does not mean nobody measured them. It means EPA has not set an enforceable maximum for that specific substance, so there is no number the utility can be in violation of.
Some are regulated indirectly — chloroform and bromodichloromethane are components of total trihalomethanes, which is regulated as a group. Hexavalent chromium is not federally regulated on its own.
"Legal" and "no limit exists" are different statements, and a page that treats them as the same is misleading in one direction or the other.
Two numbers, two questions
Every contaminant here sits between an enforceable federal limit and a stricter voluntary health guideline, and the gap between them is often large.
The EPA limit is what is achievable at reasonable cost with available treatment. The EWG guideline reflects a more conservative reading of long-term risk with no feasibility constraint. Neither is wrong — they answer different questions, and which one you find meaningful is a judgement rather than a fact.
What actually helps
Activated carbon handles most of what is on this list. By-products adsorb readily, which makes them among the more straightforward things to remove at the point of use.
Whole-house versus under-sink is a real decision here rather than an upsell. Trihalomethanes are volatile, so a hot shower is a genuine exposure route. If the goal is only better drinking water, under-sink is cheaper and sufficient.
Ask which disinfectant before buying anything. Standard activated carbon handles free chlorine easily and chloramine poorly; catalytic carbon is the one that works on chloramine.
Where you sit matters
Everything above is a system-wide figure. By-product levels rise the further water travels, because the reaction continues in the distribution main. A house at the end of a long run reads higher than one near the plant, on the same system and the same day.
The full profile and compliance record for MAWSS and every other system in Mobile and Baldwin County is published here, each with its PWSID and a link to the EPA source. For what is arriving at your address rather than across the network, the free test is the direct answer.
Contaminant data from the EWG Tap Water Database for PWSID AL0001005; compliance history from EPA SDWIS. Current as of 19 August 2026.