Category Archives: Michigan

Water Conservation for Michigan – Why?

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The Michigan Association of Planners is big on water conservation, joining several environmental groups to demand legislation requiring water conservation:

POLICY 4. Water Conservation: The Michigan Association of Planning supports state legislation requiring water conservation for public, and private users.

Among the classic legislation passed so far are laws requiring low flush toilets, and prohibiting high-volume shower heads as in this Seinfeld episode. I suppose I should go along: I’m running for water commissioner, and consider myself a conservationist. The problem is, I can’t see a good argument for these laws for most people here in Oakland County, or in neighboring Macomb and Wayne Counties. The water can’t run out because most users take it from the river and return it to the river, cleaned after it’s used; it’s all recycled.

Map of the main drinking-water pipes serving south-east Michigan

Map of the main drinking-water pipes serving south-east Michigan

The map above shows the clean water system for south-east Michigan. The high-population areas, the ones that are colored in the map, get their water from the Detroit River or from Lake Huron. It’s cleaned, pumped, and carried to your home along the pipes shown. Then after you’ve used the water, it travels back along another set of pipes to the water treatment plant and into the Detroit River.

Three-position shower head -- a wonderful home improvement I got it at universal plumbing.

Three-position shower head — a wonderful home improvement. I got it at universal plumbing.

When the system is working well, the water we return to the Detroit River is cleaner than the water we took in. So why legislate against personal use? If a customer wants to enjoy a good shower, and is willing to pay for the water at 1.5¢ per gallon, who cares how much water that customer uses? I can understand education efforts, sort-of, but find it hard to push legislation like we have against a high-volume shower head. We can not run out, and the more you use, the less everyone pays per gallon. A great shower head is a great gift idea, in my opinion.

The water department does not always work well, by the way, and these problems should be solved by legislation. We give away, for $200/year, high value clean water to Nestle company and then buy it back for $100,000,000. That’s a problem. Non-flushable toilet wipes are marketed as flushable; this causes sewer blockades. Our combined sewers regularly dump contaminated water into our rivers, lakes, and basements. These problems can be solved with legislation and engineering. It’s these problems that I’m running to solve.

Robert Buxbaum, January 6, 2019. If you want to save water, either to save the earth, or because you are cheep, here are some conservation ideas that make sense (to me).

We don’t need no stinking primary clarifier

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Virtually every sewage plant of Oakland County uses the activated sludge process, shown in the layout below. Raw sewage comes in, and goes through physical separation — screening, grit removal, and a first clarifier – settling tank before moving to the activated sludge oxidation reactor. The 1st clarifier, shown at left below, removes about half of the incoming organics, but it often stinks and sometimes it “pops” bubbles of fart. This is usually during periods of low flow, like at night. When the flow is slow, it arrives at the plant as a rotting smelly mess; it’s often hard to keep the bubbles of smell down.

Typical Oakland Sewage plant, activated sludge process with a primary clarifier.

Typical Oakland County Sewage treatment plant, activated sludge process with a primary clarifier.

The smell is much improved in the oxidation reactor, analyzed here, and in the 2nd clarifier, shown above at right. Following that is a filter, an ultraviolet cleanup stage, and the liquids are discharged to a local river. In Oakland county, the solids from the two clarifiers are hauled off to a farm, or buried in a landfill. Burial in a landfill is a costly waste, as I discuss here. The throughputs for most of these treatment plants is only about 2-3 million gallons of sewage per day. But Oakland county can produce 500 million gallons of sewage per day. The majority of this goes to Detroit for treatment, and sometimes the overflow is dumped rotting and smelly, in the rivers.

A few months ago, I visited the Sycamore Creek Wastewater facility outside of Cincinnati. This is an 8 million gallon per day plant that uses the “extended aeration process”, shown in the sketch below. I noticed several things I liked: the high throughput (the plant looks no bigger than our 2-3 million gallon plants) and the lack of a bad smell, primarily. The Sycamore Creek plant had an empty hole where the primary clarifier had once been. Lacking this clarifier, the screened sewage could not sit and pop. Instead it goes directly from grit removal to the oxidation reactor, a reactor that looks no bigger than in our plants. This reactor manages a four times higher throughput, I think, because of a higher concentration of cellular catalyst. Consider the following equation derived in a previous post:

ln C°/C = kV/Q.

Here, C° and C are the incoming and exit concentrations of soluble organic; k is the reaction rate, proportional to cellular concentration, V is the volume of the reactor, Q is the flow, and ln is natural log. The higher cellular concentration in the extended aeration plant results in an increased reaction rate, k. The higher the value of k, the higher the allowed flow, Q, per reactor volume, V.

The single clarifier at the end of the Sycamore Creek plant does not look particularly big. My sense is that it deals with a lot more sludge and flow than is seen in our 2nd clarifiers because (I imaging) the sludge is higher density, thus faster settling. I expect that, without the 1 clarifier, there is extra iron and sulfate in the sludge, and more large particles too. In our plants, a lot of these things are removed in the primary clarifier. Sludge density is also increased, I think, because the Cincinnati plant recycle a greater percentage of the sludge (I list it as 90% in the diagram). Extra iron in the reactor also helps to remove phosphates from the water effluent that flows back to the river, an important pollution concern. Iron phosphates are insoluble, and thus leave with the sludge. In Oakland county’s activated sludge plants, it is typical to add iron to the reactor or clarifier. In Cincinnati’s extended aeration plant, I’m told, iron addition is generally not needed.

Typical Oakland Sewage plant, activated sludge process with a primary clarifier.

Cincinnati sewage treatment plant, extended aeration process with no primary clarifier.

The extended aeration part of the above process refers to the secondary sludge oxidizer, the continuously stirred tank reactor, or CSTR shown at lower right above. The “CSTR” is about 1/5 the volume of the main oxidation reactor and about the size of a clarifier. Oxidation in the CSTR compliments that in the main oxidizer removing organics, making bio-polymer, and improving (I think) the quality of the sludge that goes to the farms. Oxidation in the CSTR reduces the amount of sludge that goes to the farms. The sludge that does go, is  less-toxic and more concentrated in organics and minerals. I’m not sure if the CSTR product is as good as the product from an anaerobic digester, or if the CSTR is cheaper to operate, but it looks cheaper since there is no roof, and no (or minimal) heating. This secondary oxidizer is very efficient at removing organics because the cellular catalyst concentration is very high – much higher than in the main oxidizer.

During periods of high load, early morning, the CSTR seems to serve as a holding tank so that sludge does not build up in the clarifier. Too much sludge in the clarifier can start to rot, and ruin the effluent quality. The way you tell if there is too much sludge, by the way, is through a device called the “sludge judge.” I love that name. The Cincinnati plant used a centrifugal drier; none of our plants do. The Cincinnati plant had gap the bubble spots of the main oxidizer. This is good for denitrification, I’m told, an important process that I discuss elsewhere.

The liquid output of their clarifier (or ours) is not pure enough to be sent directly to the river. In this plant, the near-pure water from the clarifier is sent to a trickling filter, a bed of sand and anthracite that removes colloidal remnants. Some of our plants do the same. I suspect that the large surface area in this filter is also home to some catalysis: last stage oxidation of remaining bio-organics. On a regular basis, the filter bed is reverse-flushed to remove cellular buildup, slime, and send it to the beginning of the process. The trickling filter output is then sent to an ultraviolet, bacteria-killing step before being released to the rivers. All in all, I suspect that an extended aeration process like this is worth looking into for Oakland County, especially for our North Pontiac sewage treatment facility. That plant is particularly bad smelling, and clearly too small to treat all its sewage. Perhaps we can increase the throughput and decrease the smell at a minimal cost.

Dr. Robert E. Buxbaum, December 18, 2018. I’m running for water commissioner of Oakland county, MI. If you like, visit my campaign site. Here are some sludge jokes and my campaign song.

Term limits, in what world are they Republican or conservative?

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The desire for term limits is one of the political innovations that leaves me baffled. What is the logic, especially for conservatives or Republicans. In theory, Republicans favor any freedom that does not hurt the individual, and in theory conservatives favor things according to the Bible. Both should oppose term limits. No individual is hurt by term limits, and in the Bible, good kings, judges, and advisors should serve for life. Rehoboam, Solomon’s son, splits Israel by ignoring his father’s advisors (1 Kings 12 ff). term limits

In a more-secular context, if you have a good doctor, one who took years to learn the craft, would you get rid of him just because you’re afraid he’ll become comfortable? It’s insane personally, and worse to make a law forcing other people to do it. It suggests a paranoia of public will, the opposite of what a Democratic Republic stands for. These are laws to keep people from voting for the fellow they like! it’s like we believe ourselves to be addicts with a deadly addiction. It’s also like we believe policy is so simple and so corrupting that a beginner is always better than everyone with experience. As it happened, Rehoboam’s young councilors were more money-hungry than the old.

Protect me from making the same mistake thrice.

Protect me from making the same mistake thrice.

Michigan’s term limits are worse than most because ours are uncommonly short: 6 years for the house. 8 for the senate, 8 for governor. While I can accept an eight year  term limit for the governor, in theory he’s just an executor, I can see no basis for the short term limits on those serving in the MI house or senate. If we can’t eliminate these limits, we should at least extend them. Also I would not make the exclusion on any of these individuals life-long. If someone served in the senate say, then left and served as governor, why not let the fellow run again for senate?

For those reading this in future decades, it's funny because XI is president of China for life, something US presidents (Trump) can't be. But they can be put in prison for life.

behind bars  For those reading this in future decades, it’s funny because XI is president of China for life, something US presidents (Trump) can’t be. But they can be put in prison for life.

For the same reason, I’m not a fan of long, mandatory minimum prison sentences. It’s like we don’t trust our judges to be tough enough. If we don’t trust them, don’t elect them, or remove them. As it is, we have more people per-capita behind bars than any other nation on earth. We assume, I guess that we can’t pick a good judge, but have to make sure he or she isn’t a lenient rascal who’ll serve for life. But is that so bad? Is it better to force the judge to spit on everyone?

There are many problems with fair sentencing, but I’m inclined to say that extenuating circumstances are always relevant, and that the shortest sentence sufficient to prevent further crime is usually the best. If judges are rascals, then the way to deal with it is judicial review or un-election. As Cotton Mather said years after overseeing the Salem witch hunts: “It’s better that a hundred witches go free than that we kill a single innocent person”. With judges, as with voters, restricting choice by law seems proper only when the effect is to protect the individual, not when the effect is to increase his burden, or so it seems to me.

Robert E. Buxbaum, October 11, 2018.

Beavers, some of the best dam builders

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I ran for water commissioner in 2016 (Oakland county, Michigan; I’ll be running again in 2020), and one of my big issues was improving our rivers. Many are dirty and “flashy”. Shortly after a rain they rise too high and move dangerously fast. At other times, they become, low, smelly, and almost disappear. There are flash floods in these rivers, few fish or frogs, and a major problem with erosion. A big part of a solution, I thought, would be to add few small dams, and to refurbish a few others by adding over-flow or underflow weirs. We had a small dam in the middle of campus at Michigan State University where I’d taught, and I’d seen that it did wonders for river control, fishing, and erosion. The fellow I was running against had been removing small dams in the belief that this made the rivers “more natural”. The Sierra Club thought he was right doing this; the fishing community and some homeowners and MSU alumni thought I was. My problem was that I was a Republican running in a Democratic district. Besides, the county executive, L. Brooks Patterson (also a Republican) was a tightwad. Among my the first stops on my campaign trail was to his office, and while he liked many of my ideas, and promised to support me, he didn’t like the idea of spending money on dams. I suggested, somewhat facetiously, using beavers, and idea that’s grown on me since. I’m still not totally convinced it’s a good idea, but bear with me as I walk you through it.

Red Cedar River dam as seen from behind the Michigan State University Administration Building.

Small dam on the Red Cedar River at Michigan State University behind the Administration Building. The dam provided good fishing and canoeing, and cleaned the water somewhat.

The picture at right shows the dam on the Red Cedar River right behind the Administration building at Michigan State University, looking south. During normal times the dam slows the river flow and raises the water level high enough to proved a good canoe trail, 2 1/2 miles to Okemos. Kids would fish behind the dam, and found it a very good fishing spot. The slow flow meant less erosion, and some pollution control. The speed of flow and the height of the river are related; see calculation here. After a big rain, a standing wave (a “jump”) would set up at the dam, raising its effective height by three or four feet. Students would surf the standing wave. More importantly, the three or four feet of river rise provided retention so that the Red Cedar did little damage. Some picnic area got flooded, but that was a lot better than having a destructive torrent. Here’s some more on the benefits of dams.

Between July 31 and Aug 1 the Clinton River rose nine feet in 3 hours, sending 130,000,000 cubic feet of water and sewage to lake St Clair.

Between July 31 and Aug 1 the Clinton River rose nine feet in 3 hours, sending 130,000,000 cubic feet of water to lake St Clair.

The Sierra club supported (supports) my opponent, in part because he supports natural rivers, without dams. I think they are wrong about this, and about their political support in general. Last night, following a 1 1/2 inch rain, the Clinton River flash flooded, going from 5.2 feet depth to 14 feet depth in just two hours. My sense is that the natural state of our rivers had included beavers and beaver dams until at least the mid 1700s. I figured that a few well-designed dams, similar to those at Michigan State would do wonders to stop this. Among the key locations were Birmingham, on the Rouge, Rochester, near Oakland University, Auburn Hills, and the Clinton River gorge, and near Lawrence Technical University. If we could not afford to build man-made dams, I figured we could seed some beaver into nearby nature areas, and let the beavers dam the rivers for free. It would bring back the natural look of these areas, as in the picture below. And engineers at Lawrence Tech and Oakland University might benefit from seeing the original dam engineers at work.

Beaver dam on a branch of the Huron River. Beavers are some of the best dam builders.

Beaver dam on a branch of the Huron River. A rather professional and attractive job at a bargain price.

Beavers are remarkably diligent. Once they set about a task, they build the basics of a dam in a few days, then slowly improve it like any good craftsman. As with modern dams, beaver dams begin with vertical piles set into the river bottom. Beavers then fill in the dam with cross-pieces, moving as much as 1000 lbs of wood in a night to add to the structure and slow the flow. They then add mud. They use their hearing to detect leaks, and slowly plug the leaks till the dam is suitably tight. Most of the streams I identified are narrow and pass through wooded areas. I think a beaver might dam them in a few days. Based on the amount of wood beavers move, and the fact that beavers are shaped like big woodchucks, I was able to answer the age-old question: how much wood would a woodchuck chuck if a woodchuck could chuck wood — see my calculation here.

Me, visiting the DNR to talk beavers

Me, visiting the DNR to talk beavers

There are a few things to check out before I start hiring beavers to take care of Oakland county flooding, and I have not checked them all out yet. Beavers don’t necessarily build where you want or as solidly, and sometimes they don’t build at all. If there are no predators, beavers can get lazy and just build a low-water lodge and a high water lodge, moving from one to the other as the river rises and falls. Hiring a beaver is like hiring an artistic contractor, it seems: you don’t necessarily get what you ask for, and sometimes you get more. Given the flash flooding we have, it’s hard to picture they’d make things worse, but what do I know? In some cases, e.g. the Red Run near the 12 towns drain, the need is for more than a beaver can deliver. Still, without beavers, the need would be for a billion gallons of retention on the Clinton alone, a 10 billion dollar project if carried out as my opponent likes to build. So, with no budget to work with, my next stop was at the Department of Natural Resources Customer Service Center (Lansing). I had some nice chats with beaver experts, and I’m happy to say they liked the idea, or at least they were not opposed. I’ve yet to talk to the Michigan director of dams, and will have to see what he has to say, but so far it seems like, if I get elected in 2020, I’ll be looking for some hard-working beavers, willing to relocate. I’d like to leave it to Beaver.

Robert E. Buxbaum, August 2, 2018. I still don’t get the Sierra Club’s idea of what a natural river would look like, or their commitment to Democrats. In my opinion, a river should include beavers, fish, and fishermen, and drainage should be done by whoever can do it best. Sierra club folks are welcomed to comment below.

Activated sludge sewage treatment bioreactors

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I ran for water commissioner of Oakland county in 2016, a county with 1.3 million people and eight sewage treatment plants. One of these plants uses the rotating disk contractor, described previously, but the others process sewage by bubbling air through it in a large tank — the so-called, activated sludge process. A description is found here in Wikipedia, but with no math, and thus, far less satisfying than it could be. I thought I might describe this process relevant mathematics, for my understanding and those interested: what happens to your stuff after you flush the toilet or turn on the garbage disposal.

Simplified sewage plant: a plug-flow reactor with a 90+% solids recycle used to maintain a high concentration of bio-catalyst material.

Simplified sewage plant: a bubbling, plug-flow bio-reactor with 90% solids recycle and a settler used to extract floc solids and bio-catalyst material.

In most of the USA, sanitary sewage, the stuff from your toilet, sink, etc. flows separately from storm water to a treatment plant. At the plant, the sewage is first screened (rough filtered) and given a quick settle to remove grit etc. then sent to a bubbling flow, plug-flow bioreactor like the one shown at right. Not all cities use this type of sludge processes, but virtually every plant I’ve seen does, and I’ve come to believe this is the main technology in use today.

The sewage flows by gravity, typically, a choice that provides reliability and saves on operating costs, but necessitates that the sewage plant is located at the lowest point in the town, typically on a river. The liquid effluent of the sewage, after bio-treatment is typically dumped in the river, a flow that is so great more than, during dry season, more than half the flow of several rivers is this liquid effluent of our plants – an interesting factoid. For pollution reasons, it is mandated that the liquid effluent leaves the plant with less than 2 ppm organics; that is, it leaves the plant purer than normal river water. After settling and screening, the incoming flow to the bio-reactor typically contains about 400 ppm of biomaterial (0.04%), half of it soluble, and half as suspended colloidal stuff (turd bits, vegetable matter, toilet paper, etc). Between the activated sludge bio-reactor and the settler following it manage to reduce this concentration to 2 ppm or less. Soluble organics, about 200 ppm, are removed by this cellular oxidation (metabolism), while the colloidal material, the other 200 ppm, is removed by adsorption on the sticky flocular material in the tank (the plug-flow tank is called an oxidation ditch, BTW). The sticky floc is a product of the cells. The rate of oxidation and of absorption processes are proportional to floc concentration, F and to organic concentration, C. Mathematically we can say that

dC/dt = -kFC

where C and F are the concentration of organic material and floc respectively; t is time, and k is a reaction constant. It’s not totally a constant, since it is proportional to oxygen concentration and somewhat temperature dependent, but I’ll consider it constant for now.

As shown in the figure above, the process relies on a high recycle of floc (solids) to increase the concentration of cells, and speed the process. Because of this high recycle, we can consider the floc concentration F to be a constant, independent of position along the reactor length.

The volume of the reactor-ditch, V, is fixed -it’s a concrete ditch — but the flow rate into the ditch, Q, is not fixed. Q is high in the morning when folks take showers, and low at night. It’s also higher — typically about twice as high — during rain storms, the result of leakage and illegal connections. For any flow rate, Q, there is a residence time for a bit of sewage flowing through a tank, τ = V/Q. We can now solve the above equation for the value of τ for an incoming concentration C° = 400 ppm, an outgoing concentration Co of 2 ppm. We integrate the equation above and find that:

ln (C°/Co) = kFτ

Where τ equals the residence time, τ = V/Q. Thus,

ln (C°/Co) = kFV/Q.

The required volume of reactor, V, is related to the flow rate, Q, as follows for typical feed and exit concentrations:

V = Q/kF ln( 400/2) = 5.3 Q/kF.

The volume is seen to be dependent on F. In Oakland county, tank volume V is chosen to be one or two times the maximum expected value of Q. To keep the output organic content to less than 2 ppm, F is maintained so that kF≥ 5.3 per day. Thus, in Oakland county, a 2 million gallon per day sewage plant is built with a 2-4 million gallon oxidation ditch. The extra space allows for growth of the populations and for heavy rains, and insures that most of the time, the effluent contains less than 2 ppm organics.

Bob Martin by the South Lyon, MI, Activated Sludge reactor

Bob Martin chief engineer the South Lyon, MI, Activated Sludge plant, 2016. His innovation was to control the air bubblers according to measurements of the oxygen content. The O2 sensor is at bottom; the controller is at right. When I was there, some bubblers were acting up.

As you may guess, the activated sludge process requires a lot of operator control, far more than the rotating disk contractor we described. There is a need for constant monitoring and tweaking. The operator deals with some of the variations in Q by adjusting the recycle amount, with other problems by adjusting the air flow, or through the use of retention tanks upstream or downstream of the reactor, or by adding components — sticky polymer, FeCl3, etc. Finally, in have rains, the settler-bottom fraction itself is adjusted (increased). Because of all the complexity. sewer treatment engineer is a high-pay, in demand, skilled trade. If you are interested, contact me or the county. You’ll do yourself and the county a service.

I’d mentioned that the effluent water goes to the rivers in Oakland county. In some counties it goes to the fields, a good idea, I think. As for the solids, in Oakland county, the solid floc is concentrated to a goo containing about 5% solids. (The goo is called unconsolidated sludge) It is shipped free to farmer fields, or sometimes concentrated to more than 5% (consolidated sludge), and provided with additional treatment, anaerobic digestion to improve the quality and extract some energy. If you’d like to start a company to do more with our solids, that would be very welcome. In Detroit the solids are burned, a very wasteful, energy-consuming process, IMHO. In Wisconsin, the consolidated sludge is dried, pelletized, and sold as a popular fertilizer, Milorganite.

Dr. Robert Buxbaum, August 1, 2017. A colleague of mine owned (owns?) a company that consulted on sewage-treatment and manufactured a popular belt-filter. The name of his company: Consolidated Sludge. Here are some sewer jokes and my campaign song.

Nestle pays 1/4,000 what you pay for water

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When you turn on your tap or water your lawn, you are billed about 1.5¢ for every gallon of water you use. In south-east Michigan, this is water that comes from the Detroit river, chlorinated to remove bacteria, e.g. from sewage, and delivered to you by pipe. When Nestle’s Absopure division buys water, it pays about 1/4000 as much — $200/ year for 218 gallons per minute, and they get their water from a purer source, a pure glacial aquifer that has no sewage and needs no chlorine. They get a far better deal than you do, in part because they provide the pipes, but it’s mostly because they have the financial clout to negotiate the deal. They sell the Michigan water at an average price around $1/gallon, netting roughly $100,000,000 per year (gross). This allows them to buy politicians — something you and I can not afford.

Absopure advertises that I t will match case-for-case water donations to Flint. Isn't that white of them.

Absopure advertises that I t will match case-for-case water donations to Flint. That’s awfully white of them.

We in Michigan are among the better customers for the Absopure water. We like the flavor, and that it’s local. Several charities purchase it for the folks of nearby Flint because their water is near undrinkable, and because the Absopure folks have been matching the charitable purchases bottle-for bottle. It’s a good deal for Nestle, even at 50¢/gallon, but not so-much for us, and I think we should renegotiate to do better. Nestle has asked to double their pumping rate, so this might be a good time to ask to increase our payback per gallon. So far, our state legislators have neither said yes or no to the proposal to pump more, but are “researching the matter.” I take this to mean they’re asking Nestle for campaign donations — the time-honored Tammany method. Here’s a Detroit Free Press article.

I strongly suspect we should use this opportunity to raise the price by a factor of 400 to 4000, to 0.15¢ to 1.5¢ per gallon, and I would like to require Absopure to supply a free 1 million gallons per year. We’d raise $300,000 to $3,000,000 per year and the folks of Flint would have clean water (some other cities need too). And Nestle’s Absopure would still make $200,000,000 off of Michigan’s, clean, glacial water.

Robert Buxbaum, May 15, 2017. I ran for water commissioner, 2016, and have occasionally blogged about water, E.g. fluoridation, hidden rivers, and how you would drain a swamp, literally.

Rethinking fluoride in drinking water

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Fluoride is a poison, toxic tor a small child in doses of 500 mg, and toxic to an adult in doses of a few thousand mg. It is a commonly used rat poison that kills by robbing the brain of the ability to absorb oxygen. In the form of hydrofluoric acid, it is responsible for the deaths of more famous chemists than any other single compound: Humphrey Davy died trying to isolate fluorine; Paul Louyet and Jerome Nickles, too. Thomas Knox nearly died, and Henri Moissan’s life was shortened. Louis-Joseph Gay Lussac, George Knox, and Louis- Jacques Thenard suffered burns and similar, George Knox was bedridden for three years. Among the symptoms of fluoride poisoning is severe joint pain and that your brain turns blue.

In low doses, though, fluoride is thought to be safe and beneficial. This is a phenomenon known as hormesis. Many things that are toxic at high doses are beneficial at low. Most drugs fall into this category, and chemotherapy works this way. Diseased cells are usually less-heartythan healthy ones. Fluoride is associated with strong teeth, and few cavities. It is found at ppm levels many well water systems, and has shown no sign of toxicity, either for humans or animals at these ppm levels. Following guidelines set by the AMA, we’ve been putting fluoride in drinking water since the 1960s at concentrations between 0.7 and 1.2 ppm. We have seen no deaths or clear evidence of any injury from this, but there has been controversy. Much of the controversy stems from a Chinese study that links fluoride to diminished brain function, and passivity (Anti-fluoriders falsely attribute this finding to a Harvard researcher, but the Harvard study merely cites the Chinese). The American dental association strongly maintains that worries based on this study are groundless, and that the advantage in lower cavities more than off-sets any other risks. Notwithstanding, I thought I’d take another look. The typical US adult consumes 1-3 mg/day the result of drinking 1-3 liters of fluoridated water (1 ppm = 1 mg/liter). This < 1/1000 the toxic dose,

While there is no evidence that people who drink high-fluoride well water are any less-healthy than those who drink city water, or distilled / filtered water, that does not mean that our city levels are ideal. Two months ago, while running for water commissioner, I was asked about fluoride, and said I would look into it. Things have changed since the 1960s: our nutrition has changed, we have vitamin D milk, and our toothpastes now contain fluoride. My sense is we can reduce the water concentration. One indication that this concentration could be reduced is shown below. Many industrial countries that don’t add fluoride have similar tooth decay rates to the US.

World Health Organization data on tooth decay and fluoridation.

World Health Organization data on tooth decay and fluoridation.

This chart should not be read to suggest that fluoride doesn’t help; all the countries shown use fluoride toothpaste, and some give out fluoride pills, too. And some countries that don’t add fluoride have higher levels of cavities. Norway and Japan, for example, don’t add fluoride and have 50% more cavities than we do. Germany doesn’t add fluoride, and has fewer cavities, but they hand out fluoride pills, To me, the chart suggests that our levels should go down, though not to zero. In 2015, the Department of Health recommend lowering the fluoride level to 0.7 ppm, the lower end of the previous range, but my sense from the experience of Europe is that we should go lower still. If I were to pick, I’d choose 1/2 the original dose: 0.6 to 0.35 ppm. I’d then revisit in another 15 years.

Having picked my target fluoride concentration, I checked to see the levels in use in Oakland county, MI, the county I was running in. I was happy to discover that most of the water the county drinks, that provided by Detroit Water and Sewage, NOCWA and SOCWA already have decreased levels of 0.43-0.55 ppm. These are just in the range I would have picked, Fluoride concentrations are higher in towns that use well water, about  0.65-0.85 ppm. I do not know if this is because the well water comes from the ground with these fluoride concentrations or if the towns add, aiming at the Department of Health target. In either case, I don’t find these levels alarming. If you live none of these town, or outside of Oakland county, check your fluoride levels. If they seem high, write to your water commissioner. You can also try switching from fluoride toothpaste to non-fluoride, or baking soda. In any case, remember to brush. That does make a difference, and it’s completely non-toxic.

Robert Buxbaum, January 9, 2017. I discuss chloride addition a bit in this essay. As a side issue, a main mechanism of sewer pipe decay seems related to tooth decay. That is the roofs of pipe attract acid-producing, cavity causing bacteria that live off of the foul sewer gas. The remedies for pipe erosion include cleaning your pipes regularly, having them checked by a professional once per year, and repairing cavities early. Here too, it seems high fluoride cement resists cavities better.

How do you drain a swamp, literally

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The Trump campaign has been claiming it wants to “drain the swamp,” that is to dispossess Washington’s inbred army of academic consultants, lobbyists, and reporter-spin doctors, but the motto got me to think, how would you drain a swamp literally? First some technical definitions. Technically speaking, a swamp is a type of wetland distinct from a marsh in that it has no significant flow. The water just, sort-of sits there. A swamp is also unlike a fen or a bog in that swamp water contains enough oxygen to support life: frogs, mosquitos, alligators,., while a fen or bog does not. Common speech ignores these distinctions, and so will I.report__jaguars_running_back_denard_robi_0_5329357_ver1-0_640_360

If you want to drain a large swamp, such as The Great Dismal Swamp that covered the south-east US, or the smaller, but still large, Hubbard Swamp that covered south-eastern Oakland county, MI, the classic way is to dig a system of open channel ditches that serve as artificial rivers. These ditches are called drains, and I suppose the phrase, “drain the swamp comes” from them. As late as the 1956 drain code, the width of these ditch-drains was specified in units of rods. A rod is 16.5 feet, or 1/4 of a chain, that is 1/4 the length of the 66′ surveyor’s chains used in the 1700’s to 1800’s. Go here for the why these odd engineering units exist and persist. Typically, 1/4 rod wide ditches are still used for roadside drainage, but to drain a swamp, the still-used, 1956 code calls for a minimum of a 1 rod width at the top and a minimum of 1/4 rod, 4 feet, at the bottom. The sides are to slope no more than 1:1. This geometry is needed. experience shows, to slow the flow, avoid soil erosion and help keep the sides from caving in. It is not unusual to add one or more weirs to control and slow the flow. These weirs also help you measure the flow.

The main drain for Royal Oak and Warren townships, about 50 square miles, is the Red Run drain. For its underground length, it is 66 foot wide, a full chain, and 25 feet deep (1.5 rods). When it emerges from under ground at Dequindre rd, it expands to a 2 chain wide, open ditch. The Red Run ditch has no weirs resulting in regular erosion and a regular need for dredging; I suspect the walls are too steep too. Our county needs more and more drainage as more and more housing and asphalt is put in. Asphalt reduces rain absorption and makes for flash floods following any rain of more than 1″. The red run should be improved, and more drains are needed, or Oakland county will become a flood-prone, asphalt swamp.

Classic ditch drain, Bloomfiled MI. Notice the culverts used to convey water from the ditch under the road.

Small ditch drain, Bloomfield, MI. The ditches connect to others and to the rivers via the culvert pipes in the left and center of the picture. A cheap solution to flooding.

Ditch drains are among the cheapest ways to drain a swamp. Standard sizes cost only about $10/lineal foot, but they are pretty ugly in my opinion, they fill up with garbage, and they tend to be unsafe. Jaguars running back Denard Robinson was lucky to have survived running into one in his car (above) earlier this year. Ditches can become mosquito breeding grounds, too and many communities have opted for a more expensive option: buried, concrete or metal culverts. These are safer for the motorist, but reduce ground absorption and flow. In many places, we’ve buried whole rivers. We’ve no obvious swamps but instead we get regular basement and road flooding, as the culverts still have combined storm and sanitary (toilet) sewage, and as more and more storm water is sent through the same old culverts.

Given my choice I would separate the sewers, add weirs to some of our ditch drains, weirs, daylight some of the hidden rivers, and put in French drains and bioswales, where appropriate. These are safer and better looking than ditches but they tend to cost about $100 per lineal foot, about 10x more than ditch drains. This is still 70x cheaper than the $7000/ft, combined sewage tunnel cisterns that our current Oakland water commissioner has been putting in. His tunnel cisterns cost about $13/gallon of water retention, and continue to cause traffic blockage.

Bald cypress swamp

Bald cypress in a bog-swamp with tree knees in foreground.

Another solution is trees, perhaps the cheapest solution to drain a small swamp or retention pond, A full-grown tree will transpire hundreds of gallons per day into the air, and they require no conduit connecting the groundwater to a river. Trees look nice and can complement French drains and bioswales where there is drainage to river. You want a species that is water tolerant, low maintenance, and has exceptional transpiration. Options include the river birch, the red maple, and my favorite, the bald cypress (picture). Bald cypress trees can live over 1000 years and can grow over 150 feet tall — generally straight up. When grown in low-oxygen, bog water, they develop knees — bits of root-wood that extend above the water. These aid oxygen absorption and improve tree-stability. Cypress trees were used extensively to drain the swamps of Israel, and hollowed-out cypress logs were the first pipes used to carry Detroit drinking water. Some of these pipes remain; they are remarkably rot-resistant.

Robert E Buxbaum, December 2, 2016. I ran for water commissioner of Oakland county, MI 2016, and lost. I’m an engineer. While teaching at Michigan State, I got an appreciation for what you could do with trees, grasses, and drains.

The straight flush

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I’m not the wildest libertarian, but I’d like to see states rights extended to Michigan’s toilets and showers. Some twenty years ago, the federal government mandated that the maximum toilet flush volume could be only 1.6 gallons, the same as Canada. They also mandated a maximum shower-flow law, memorialized in this Seinfeld episode. Like the characters in those shows, I think this is government over-reach of states rights covered by the 10th amendment. As I understand it, the only powers of the federal government over states are in areas specifically in the constitution, in areas of civil rights (the 13th Amendment), or in areas of restraint of trade (the 14th Amendment). None of that applies here, IMHO. It seems to me that the states should be able to determine their own flush and shower volumes.

If this happen to you often, you might want to use more water for each flush, or at least a different brand of toilet paper.

If your toilet clogs often, you might want to use more flush water, or at least a different brand of toilet paper.

There is a good reason for allowing larger flushes, too in a state with lots of water. People whose toilets have long, older pipe runs find that there is insufficient flow to carry their stuff to the city mains. Their older pipes were designed to work with 3.5 gallon flushes. When you flush with only 1.6 gallons, the waste only goes part way down and eventually you get a clog. It’s an issue known to every plumber – one that goes away with more flush volume.

Given my choice, I’d like to change the flush law through the legislature, perhaps following a test case in the Supreme court. Similar legislation is in progress with marijuana decriminalization, but perhaps it’s too much to ask folks to risk imprisonment for a better shower or flush. Unless one of my readers feels like violating the federal law to become the test case, I can suggest some things you can do immediately. When it comes to your shower, you’ll find you can modify the flow by buying a model with a flow restrictor and “ahem” accidentally losing the restrictor. When it comes to your toilet, I don’t recommend buying an older, larger tank. Those old tanks look old. A simpler method is to find a new flush cistern with a larger drain hole and flapper. The drain hole and flapper in most toilet tanks is only 2″ in diameter, but some have a full 3″ hole and valve. Bigger hole, more flush power. Perfectly legal. And then there’s the poor-man solution: keep a bucket or washing cup nearby. If the flush looks problematic, pour the extra water in to help the stuff go down. It works.

A washing cup.

A washing cup. An extra liter for those difficult flushes.

Aside from these suggestions, if you have clog trouble, you should make sure to use only toilet paper, and not facial tissues or flushable wipes. If you do use these alternatives, only use one sheet at a flush, and the rest TP, and make sure your brand of wipe is really flushable. Given my choice, I would like see folks in Michigan have freedom of the flush. Let them install a larger tank if they like: 2 gallons, or 2.5; and I’d like to see them able to use Newman’s Serbian shower heads too, if it suits them. What do you folks think?

Dr. Robert E. Buxbaum, November 3, 2016. I’m running for Oakland county MI water resources commissioner. I’m for protecting our water supply, for better sewage treatment, and small wetlands for flood control. Among my less-normative views, I’ve also suggested changing the state bird to the turkey, and ending daylight savings time.

Weir dams to slow the flow and save our lakes

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As part of explaining why I want to add weir dams to the Red Run drain, and some other of our Oakland county drains, I posed the following math/ engineering problem: if a weir dam is used to double the depth of water in a drain, show that this increases the residence time by a factor of 2.8 and reduces the flow speed by 1/2.8. Here is my solution.

A series of weir dams on Blackman Stream, Maine. Mine would be about as tall, but somewhat further apart.

A series of weir dams on Blackman Stream, Maine. Mine would be about as tall, but wider and further apart. The dams provide oxygenation and hold back sludge.

Let’s assume the shape of the bottom of the drain is a parabola, e.g. y = x2 , and that the dams are spaced far enough apart that their volume is small compared to the volume of water. We now use integral calculus to calculate how the volume of water per mile, V is affected by water height:  V =2XY- ∫ y dx = 2XY- 2/3 X3 =  4/3 Y√Y. Here, capital Y is the height of water in the drain, and capital X is the horizontal distance of the water edge from the drain centerline. For a parabolic-bottomed drain, if you double the height Y, you increase the volume of water per mile by 2√2. That’s 2.83, or about 2.8 once you assume some volume to the dams.

To find how this affects residence time and velocity, note that the dam does not affect the volumetric flow rate, Q (gallons per hour). If we measure V in gallons per mile of drain, we find that the residence time per mile of drain (hours) is V/Q and that the speed (miles per hour) is Q/V. Increasing V by 2.8 increases the residence time by 2.8 and decreases the speed to 1/2.8 of its former value.

Why is this important? Decreasing the flow speed by even a little decreases the soil erosion by a lot. The hydrodynamic lift pressure on rocks or soil is proportional to flow speed-squared. Also, the more residence time and the more oxygen in the water, the more bio-remediation takes place in the drain. The dams slow the flow and promote oxygenation by the splashing over the weirs. Cells, bugs and fish do the rest; e.g. -HCOH- + O2 –> CO2 + H2O. Without oxygen, the fish die of suffocation, and this is a problem we’re already seeing in Lake St. Clair. Adding a dam saves the fish and turns the run into a living waterway instead of a smelly sewer. Of course, more is needed to take care of really major flood-rains. If all we provide is a weir, the water will rise far over the top, and the run will erode no better (or worse) than it did before. To reduce the speed during those major flood events, I would like to add a low bicycle path and some flood-zone picnic areas: just what you’d see on Michigan State’s campus, by the river.

Dr. Robert E. Buxbaum, May 12, 2016. I’d also like to daylight some rivers, and separate our storm and toilet sewage, but those are longer-term projects. Elect me water commissioner.