Locally, water quality issues are a big deal right now with the Florida DEP revising water quality regulations and the heavy rainfall causing more water to be released from Lake Okeechobee which is causing problems. The Lake Okeechobee situation is a "real" problem that is going to take a few more decades to "solve" and after that there will still be problems when there is a heavy rain period following an extended drought period. The water quality regulation issue is a non-issue being promoted it appears to recapture some of its former environmental activism glory.
For Lake Okeechobee, in spite of huge residential and commercial development since 1930, the primary villain is "Big Sugar". Big Sugar uses fertilizer and runoff tends to favor invasive plants more than native plants. To reduce the problem Big Sugar has adjusted their practices a bit and built artificial wetlands to filter mainly Potassium runoff. The complete Everglades restoration plan is extremely ambitious and involves among other things installing nearly 100 miles of new bridges on the Tamiami Trail and other roadways to make the 'glades water flow more "normal". To work properly, all of this has to be designed for extreme conditions like hurricane monsoons that flooded areas in the 1920s killing a few thousand people leading to the installation of the dikes, roads, and canals that are the problem now.
There are lots of things that can improve the situation, but nothing that will prevent all problems and some of the "solutions" will create new problems. Such is life. Most of the current issues will resolve themselves as rainfall returns to "normal" and in the mean time the flushing is probably a good thing. In any case, most of the projects have to be on hold until rains slow down enough to do the work.
The other situation, water quality, is a function of incorporating 30 years of research and determining new levels of "acceptable" risk. This is extremely interesting because 30 years of linear no threshold modeling and 1 in a million risk being used as an approximation of zero has totally screwed up lay logic.
1 in million in the US is different than 1 in a million in the UK, or can be. Depending on the issue, 1 in a million might be figured over a 70 year lifetime or over one year which is a huge difference. If you have been using one "standard" and try to change to a new standard, political affiliation becomes a factor. 1 in a million annually is about 1 in 14,000 lifetime which is still 10,000 times less likely than dying while driving to work over a lifetime.
Washington State has an issue with water quality limits and salmon. This gets to be interestingly complicated because you have to estimate how much salmon someone might eat per lifetime, the bio-accumulation rate plus the level that might cause an unacceptable risk of something happening. Since people seem to love fad diets, a new salmon diet could be 250 grams of salmon per day, 365.25 day per year for 70 years ignoring other fad diets that might interfere and the likelihood that an all salmon diet might not be all that healthy to being with. What the local Governor wanted to do is change the lifetime risk from 1 in a million to 1 in 100,000. One in a million is like flipping 20 coins at once and all landing on heads while 1 in 100,000 is like making it just 17 coins instead, more like 16.5 coins but who's counting.
When Mercury in tuna became an issue, it was because a couple of fad dieters ate high dollar Albacore, 2 to 3 times a day for a year or two and started having their hair fall out. Albacore has about 3 times as much Mercury as "average" tuna and tuna 3 times a day, everyday, forever, is in the ballpark of 200 times more than "normal" unless you happen to be a tuna eating predator.
Neither of the tuna fad dieters died and after 6 months their Mercury levels returned to something close to normal. One became a devoted advocate for "proper" labeling of Mercury and destroying millions of tons of tuna that exceed the limits they think are reasonable. In case you miss this subtle point, having a whacked out nut job establish reasonable limits is beyond bizarre.
Now add climate change activism. About 17% of all the anthropogenic Mercury in the environment is due to coal emissions from "average" coal fired plants. About 60% is related to mining in general with the majority related to "artisan" mining which is low tech third world practices. So climate change activists ignore reality and use Mercury-coal for leverage to steer policy. North America, which includes the US, is responsible for 7% of global mercury emissions with natural causes accounting for nearly half of that 7 percent. Don't forget that other types of mining also takes place in the US though with stricter regulation, so the actual US coal contribution might be 1% to 3% of global emissions.
Lead mining/smelting contributes to the Mercury problem as well. Doe Run was the last lead smelting operation in the US and had developed an electro-separation method to produce lead in a "green" manner. Because of costs and regulatory uncertainty, Doe Run dropped its plans for a new green plant and ships lead ore to China so "artisans" can do the smelting job then ship the lead back to the US. This "clean" solution increases Mercury pollution along with adding quite a few tons of other pollutants to the environment, but tends to satisfy "activist" environmental science fans.
Fracking is unpopular and since fracking fluids that return from a well have Benzene levels and Benzene is a carcinogen, Linda Young, a Florida Clean Water "expert" noticed that Florida, currently with a Republican Governor, wanted to raise Benzene levels from 1.18 PPB to <2.0 PPB when revising the Florida clean water act standards. It appears that the original data published to bash the revised standard mistakenly used <2.0 PPM, which was likely a typo, but the increase in allowed "toxins" by 1000 times by a Republican administration got pretty good media coverage. Linda has a MA in Political Science and Communications and has been the "director" of Florida Clean Water Network for over 21 years and it was her website that broke the story. Confusing Part Per Million with Parts Per Billion is unfortunately fairly common. Happens to the best of folks. Running with an alarming story without fact checking is also fairly common. Thinkprogress jumped all over the story, which is something "real" science advocates might want to consider. The original 1000 times has disappeared and been replaced by a more believable but still exaggerated 3 times.
Personally, I have no problem letting wannabe science activists make a case on false data so I can humiliate them to no end. At my age it is pretty enjoyable making geniuses look like idiots. During this political campaign season, my little hobby seems to be becoming popular. I cannot take credit for the fad though. Unfortunately, it is a bit of an inside joke since many of the self proclaimed "experts" aren't bright enough to get it, like the Food Babe for example. See science you can defend, but pseudoscience is a belief system and there is a saying that "you can't fix stupid."