When I started writing stories about Great Lakes ecology in the late 1980s, an activist said something that sounded profound. Thinking back to the earlier, algae-choked days on Lake Erie, she said: “Today there’s less sewage, but more poison.”

By poison, she meant synthetic chemicals with long, unpronounceable names, known by their initials (DDT, PCBs) or short forms (dioxin). Some were pesticides, and some were just accidental byproducts of industry, the stuff people used to dump anywhere without understanding the harm.

Today the picture is changing again. Those synthetic chemicals do last a long time, but we’ve stopped manufacturing and dumping most of them. No one makes mirex or PCBs today. Eventually the chemical residues will break down.

What we do produce in enormous quantities is manure. Federal figures show that Ontario and Quebec together produce manure equivalent to the sewage from 100 million people. It is sprayed, mixed with water, on fields near the Great Lakes, especially lakes Huron and Erie, and the smaller St. Clair.

I’ve been uncomfortable with this for some time. Then a few weeks ago, the environmental commissioner for Ontario came to Ottawa. Gord Miller dropped in to the Citizen for a chat and mentioned that he had just given a speech to a conference on fresh water in Bracebridge, the heart of the Muskoka region.

Miller argued in his speech that the biggest threat to Ontario’s water isn’t toxic waste. It’s manure.

Manure is called “nutrients” in official circles, but in reality it’s foul-smelling brown stuff, especially the manure from factory farms that is kept in huge vats, fermenting a bit, and sprayed on fields in spring and fall. (And sometimes winter. They shouldn’t do this because it runs off frozen land in spring into lakes and rivers, but people sometimes do it anyway.)

For years we’ve been told E. coli and other pathogenic material in fresh water comes from both farm animals and from humans, the implication that both groups are equally part of the problem. But a recent study of Lake Huron looked at the DNA of E. coli. It shows that only about one to three per cent of the lake’s E. coli come from humans — and about 60 per cent comes from livestock manure. The rest is either unknown or from wildlife.

So human sewage isn’t the problem. The problem is the spraying of more animal manure than the land can soak up.

If you wonder why we haven’t heard more about this, Miller had an answer for that too.

The Great Lakes have wave action that keeps such pollution close to shore, where people swim.

But until very recently, Miller says, surveys of lake water quality were done by boats that are too big to approach shore. They’ve been sampling farther out, in deep water that’s cleaner — and missing the true picture.

Luckily the commish is on top of this. He says sampling procedures have improved. We do hope his next survey of Ontario’s environmental health tells everyone what’s been happening.

And yet Canadian and U.S. pollution regulations still focus on the enemies of the 1970s, the remnants of days when the chemical factories dumped waste material in a shallow hole out back, near the local river or lake. That’s yesterday’s problem. It’s time to focus on the real, Walkerton-style pollution. There’s less poison today, but more animal sewage.

This problem appears to threaten more than our waterways. At Newcastle University in England, scientists have been measuring how natural bacteria change over time. In farm soil, they’ve found something odd: soil bacteria are showing genetic signs of resistance to a variety of antibiotics. Professor David Graham, who led the research, said the findings suggest an emerging threat to public and environmental health.

Graham’s point is that drug resistance in infectious disease bugs is a known threat. It most often takes the form of “superbugs” that infect people, often in hospitals. A common one is MRSA, a staphylococcus bug that resists the drug methicillin.

We know that hot spots of drug-resistance in soil bacteria are often near hog farms. Pigs get antibiotics in their food regularly, sick or not, and the drugs are flushed out with the manure. In high volume, this is enough to change those soil bacteria.

But then again, soil bacteria don’t affect us directly, right? They help crops grow, and it doesn’t matter, does it, whether they can resist antibiotics?

Turns out these bugs may affect us after all. Back at Newcastle, Graham points out that harmless soil bacteria could pass on a resistant gene to a disease-causing pathogen, such as MRSA, with obvious consequences. (Bacteria are weird; they borrow genes from each other, and from their hosts.)

Manure, anyone?

via Misgivings about manure.