Every word of the OP is either false or stupid.
"Raw sewage" has been dumped into flowing estuaries since before humans existed. It is outlawed to some extent because we humans consider it "icky" to recreate (swim, fish, boat, jet-ski) in waters into which human waste has been dumped. Since the beginning of human waste treatment, the amount of sewage dumped has been gradually decreasing, but there has always been a limit on how much waste can be treated in existing facilities, and for the past hundred years or so, much of municipal treatment has been compromised because the waste treatment facilities receive not only waste from "sanitary" sewers, but also from STORM sewers. So that when there is a significant rainstorm, the overflow (poop) necessarily flows into the estuary.
Municipal waste treatment systems - pushed by the Federal government - have been doing everything feasible (assuming limited financial resources) to (a) separate the sanitary sewers from the storm sewers, (b) build holding ponds to hold the overflow when there is a storm, and (c) increase the capacity of the sewer systems. This three-fold campaign has been going on for DECADES, resulting in many billions of dollars being spent by agencies and "authorities" out of the limited funds people are willing to devote to treating poop. The Obama Administration decreed a hyper-expensive ramp-up of this campaign - as with all Democrat initiatives, "To Hell with the Cost, we need to DO IT NOW!" - and the Trump Administration has allowed this never-ending process to slow down a bit, to take the financial pressure off wastewater treatment authorities to spend more money THAT THEY MUST BORROW TO DO THE WORK.
But here's the thing. Ever wonder what happens to all that poop? It has been building up for hundreds of years, right?
No. The living things in the estuary gradually consume and neutralize the biologicals in the waste stream sufficiently - and this is the important part - so that it is not long dangerous, and so that the WATER TREATMENT INTAKE of the next town down the stream can use that water to begin to treat its own DRINKING WATER. In fact, it is often said that the function of a Wastewater Treatment Plant is to duplicate and accelerate the natural treatment processes that already exist in the aforementioned estuary.
Not to worry. We will not die prematurely due to Trump's scale-back of these regulations.