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What should go down the toilet? Besides the obvious, shouldn’twe have a list of things that should only go down a toilet? It seemslike we tend to make lists of things that should not go down a toi-let, which leaves us open to getting things that are not on the listdown the toilet. For example, how many times have you found aG.I. Joe doll at your wastewater treatment plant? It obviously wasflushed down the toilet, but since it was not on our list of things tonot flush down the toilet, somebody obviously thought it was okay(no jokes about what you found in the Kung Fu grip either!).

Part of the new SSO rule (for the state of Wisconsin) that waspassed last year contains the need for a CMOM document and itsimplementation. Part of the CMOM is a review of your ordi-nances, and part of your ordinances should include what shouldgo down a toilet and what shouldn’t go down a toilet.

So what should go down? Well, that’s for you to

decide. Besides the biological portions of the list, you shouldmake the decisions on grease, waste oils, householdcleaners/chemicals and other materials that one may find aroundthe average home. Industries add a significant amount of non-domestic chemicals and they can add large volumes of these mate-rials. Are you going to allow the dairy to dump large amounts ofmilk? Are you going to let the farm equipment business dumppaint booth chemicals and phosphoric acid metal prep chemicalsdown the drain?

These are all things that should come up in the discussion as towhat is allowed to come into your plant. These materials willhave troublesome effects on the plant, and any fixes will cost yourtown extra money. Maybe it’s alright to have the whole communi-ty subsidizing a manufacturing plant’s waste treatment if it keepsjobs in town. Once again, it’s a decision that has to be made byyour Board, Council, and city attorney.

The newest problems for our collection systems are often simple,but can be difficult to identify at first. One example would be“flushable” wipes. The cleaning wipes that you find at the localstore all say that they are flushable. You have to look close at thefine print, but it’s there. If you ever have the time to look at one ofthese, just try to tear it apart. Pretty hard to do by hand isn’t it? Ifyou do get one apart it looks kind of like they are made of a mate-rial similar to fishing line. Well, most are made of a type of plas-tic, they shred into long strings, don’t pull apart at all and theydon’t dissolve. The code that the manufacturer of these wipes usesbasically says that after 3-hours of sloughing around in a collec-

Whatever Goes DownBy Chris Groh

tion system, if the material loses 25% of its mass they can call it“flushable”. When they test these things they really move and beatthe material around for 3 solid hours. Nothing like what youwould find in your collection system. (If you would like to seemore on these tests and results, go to www.INDA.org.)

As operators we know that these wipes will plug pumps, shearapart and the resulting fibers will wrap around impellers or shafts(causing failures). And as they’re not biodegradable they have tobe removed from the treatment flow at the plant head-works.Many plants have installed new head-works to get around theseissues. So wouldn’t it help the municipality to recommend notflushing these materials in the first place?

1Check valve plugged with “flushable” wipes

Must Come UpThe cleaning wipes that you find at the local store all say that they are flushable.

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Spring 2014 w MRWA TODAY 45

2Wipes flushed down the drain will get caught in laterals and causebasement backups

New screens, comminutors and other means of removing thesethings are pretty expensive. You might be able to avoid these costsby educating your customers. If you bill quarterly you couldinclude a word on the effects and expense of flushing wipes downthe drain (even the ones that say they are flushable). Maybe includea couple of pictures of the wipes found in your equipment1. Alsomention that these materials are not biodegradable and they canlead to basement backups and other bad things2.

So back to the original premise of making a list of things thatshould go down a toilet. This list is actually pretty short. It’s best towork with your customers and let them know to contact the munic-ipality and ask if the material they wish to flush is allowable at theplant. Maybe you can make arrangements for additional charges totreat excessive or questionable materials at the plant.

For more information on wipes, and for ideas on educational mate-rials for your customers, I would direct you to the NationalAssociation of Clean Water Agencies website at NACWA.org.Click the “Operations and Wet Weather Issues” tab, then click on“Non-Dispersible Products” for lots of good information.

Chris Groh is a wastewater trainer for Wisconsin Rural WaterAssociation. Reprinted with permission from Wisconsin RuralWater Association Journal, Winter 2014.

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