Attack of the Killer Dishwashers

Last weekend I trained as a water analyst for the Sierra Club’s Water Sentinels program. We tested two fresh samples of water from the Kishwaukee River, one upstream from DeKalb Sanitary District operations and one downstream. I was surprised by this in a couple of ways. I had expected we’d analyze water from a rural part of the county for farm chemical runoff, for one thing. And I did not expect that the Sanitary District would be putting anything bad in the river.

And they’re not, sort of. The Sanitary District isn’t breaking any pollution laws or anything like that. It’s that our treated water is too nutritious. Seriously.

Many of the chemicals we use in and around our homes and farms contain nutrients–fertilizers–that plant life loves. When too many of these nutrients enter lakes, rivers and other surface waters these plants, especially algae, multiply like crazy. This becomes a problem for the resident wildlife if the plants block too much of the sun or if a toxic variety of algae takes hold. Of particular concern locally is that the algae “blooms” can hog too much of the oxygen, which puts the fish at risk.

Now, if you just thought, “Hey, that can’t be right. Plants take in carbon dioxide, put out oxygen. That’s good for the fish,” yes, that’s what I was thinking, too. But photosynthesis occurs only in the presence of the sun. At night, photosynthesis shuts down and the bacteria that feed on (the now-enormous amounts of) dead algae in the decomposition process suck up the dissolved oxygen in the water. Too much algae, too much O2-sucking, bye-bye fish.

Natural fresh surface water undergoes an aging process called eutrophication (eutrophic: from Greek and German meaning well fed). The process is associated with increased aquatic plant and algae growth, high nutrient content, a reduction in water clarity, and decreased dissolved oxygen content. Increased biological activity ultimately results in sedimentation as dead and decaying plant debris sinks and accumulates on the bottom of the lake or pond. In essence, surface water is transformed into a bog. Excessive inputs of P accelerate the eutrophication process of lakes.

By the end of the 1960s, a serious decline in water quality was documented for many major bodies of surface water, especially water adjacent to heavily populated areas of the eastern United States. The poor water quality of the Great Lakes, particularly Lake Erie, caused the public to stand up and take notice. Lake Erie was referred to as a dead lake…The blue pike population crashed between 1954 and 1958 and never recovered. By 1983 it was designated an extinct species.

The analysis we did is much like what home aquarium-keepers do when it comes to what we were testing for and in requiring precise measurements, procedure and timing, but the equipment is much more sophisticated. Three of the tests utilize a spectrophotometer, which the Sierra people call by its brand name, Hach (pronounced “Hock”) I suppose for the obvious pronunciation and spelling reasons.

By the time I got involved in the process, water samplers in the field had already fixed the oxygen in some of the samples, noted river level and speed of flow, air and water temperature, and whether the water looked murky or clear. (These measurements, along with pH, are helpful to know because amounts of some of the chemicals we would be looking for later are affected by them.) Back at the lab we tested pH and levels of dissolved oxygen (DO), ammonia, nitrate and phosphate (an easy way to test for phosphorus). We were hoping to find DO levels satisfactorily high, nitrate and phosphate low, ammonia as close to non-existent as possible both because it’s very toxic and because it’s already highly regulated while the other chemicals are not.

The results of the analysis were in good range except for the “downstream” phosphate test, which was off the charts. Blue. Dark, inky blue. We had to dilute the sample in a 1:5 ratio for the Hach to read it.

Flashback to my childhood, when we had very good detergents containing phosphates but at the same time had rushing rivers with major sudsing action. (Click here for a chronology of the “detergent wars.”) Phosphates in laundry detergents have since been banned for all the reasons stated above but—pssst!—they are still allowed in automatic dishwashing detergents.

I hear from my new Sierra Club acquaintances that nutrient management systems are now required for new sewage treatment plants and add-ons to plants. Cortland’s plans for sewage will incorporate this new green technology:

The Shaffer System will manage and reuse the entire town’s wastewater to produce high quality water intended for irrigation of surrounding farmland, parks and open space for the community. The Cortland residents and all new developments will enjoy the benefits the Sheaffer System has to offer and at the same time, the rivers and streams in and around Cortland will not take in one drop of sewage from a conventional treatment plant.

Dr. Jack Sheaffer, Founder and Chairman of Sheaffer Systems said, “Cortland’s wastewater will now be reclaimed for true beneficial reuse for parks, golf courses, green space and farmland rather than merely relocating it to pollute the rivers and streams. Courtland will now have a wastewater system that will be a source of pride rather than a source of headaches and liability.”

OK, it reads like a an ad for Sheaffer, but you get the idea.

It’s going to be awhile before DeKalb builds anything like that. Meanwhile, what are you going to do with your killer dishwasher? I’ve found a phosphate-free brand of detergent here in town at Duck Soup Coop (you do not have to be a member to shop there) and I hear that Trader Joe’s carries a good product, too. Save a fish–buy phosphate-free.