Category Archives: Water Treatment

Water

Colorado River Basin

I spent thirty years in the water business.  I was one of the troops, not a manager or staff person.  I did, however, do what I could to keep up with developments in the water and wastewater business.  With the Clean Water Act and the Environmental Protection Agency, rivers no longer catch fire, and our fresh water. Supply is in much better shape than, say, the 1950’s. 

I worked at the Greeley, Colorado wastewater plant for three years.  The water we sent to the river met EPA standards until the Cache La Poudre flooded and washed out the pipe carrying water from one side of the river to the other for final treatment.  Lots of raw sewage went into the river for about a week until an emergency pipeline was laid on the highway bridge next to the plant.   

An old adage in the wastewater business goes, “The solution to pollution is dilution”.  That saying is mostly obsolete, but during that flood there was plenty of water for dilution.  We had to wear hip waders to get around the north side of the plant, flooded with almost three feet of water.   

The Denver Water System

Here is a big part of the water story in the American West.  There is either too much water or not enough.  Here on the Colorado Front Range a water crisis is slowly developing.  The available water is starting to run out.  Half of Denver Water’s water supply comes under the Continental Divide from the Colorado River.  There is little more water available from the river for the Denver Metro population except from spring runoff, when there is more water than can be stored.  Most years.   

Other years, the snowpack is down, spring runoff is low, reservoirs drop, and worry starts.  Water supply fluctuates, but demand only increases.  Oh, wait, during a big drought recently,  the Denver Water Board shifted its priority from dam building and water diversion to conservation.  It worked, and continues to work, not just with Denver.  Another water source is also coming into use.   

Water law says if you use water from your nearby stream, you must return what you didn’t use to the stream.  Water users downstream get lots of their water from return flows from irrigation or wastewater plant outflows.  Water law also states that water you divert from another basin does not have to be returned.  You can use it to extinction.  So what once went downstream is being captured in new reservoirs downstream made from old gravel pits and used for water exchanges, where downstream users trade their upstream water rights for return flow water from Denver.  The potato and corn fields don’t seem to mind.   

The other thing happening is taking that foreign water, treating it, and pumping it upstream for reuse.  At this point it is mostly for irrigation of parks, golf courses, and the like, but it is also being treated to drinking water standards.  Yes, you might be drinking water that once was sewage.  Not to worry, think about Omaha, St. Louis, Memphis, and New Orleans.  What are they drinking? 

Eventually this will all end.  The water will run out.  At some point, tap fees for new housing or industry will soar and development will go elsewhere.  The growth cannot continue indefinitely.  The same thing will occur in the entire Colorado River Basin.  Despite every effort to conserve or store more water, it is going to run out.  The new growth will then go to Cincinnati and Birmingham, all those wet places back East..  They have lots of water.

Cleaning the Water

Building The Marston Plant a While Back

Building The Marston Plant a While Back

I spent 30 years in the water treatment industry.  Most of it was water treatment, but I put in three years in as a wastewater treatment operator.  The goal of both jobs is to make dirty water clean.  The processes are different, and the standards for the product differ, but the idea is to make the water safe for humans.   I wouldn’t recommend drinking wastewater plant effluent, but you can swim in it.  Water, you can drink, except in Flint. 

What about the stuff taken out of the water in order to make it safe?  In both instances the stuff is called sludge.  Sludge is nasty.  There are several kinds of wastewater sludge, some nastier than others.  The first step takes out the stuff that sinks.  In a wastewater plant,  that stuff is the nastiest.  I once fell in a pit of primary sludge, injured a finger, and lost it to infection.  In Spanish, my nickname is Nueve.    

There are several techniques to deal with wastewater sludge to render it more benign, but it still tends to stink.  (By any other name, it’s still shit.).  That sludge ends up on farmland or as compost.  Water plant sludge is treated differently, but gets used the same way. 

Water Filters

Water Filters

I spent sixteen years with Denver Water in the Marston treatment plant.  It is fed by Marston Lake with water from the South Platte River.  Most of the time South Platte water is high quality Rocky Mountain water.  At other times, the Rockies get unruly and send some dirty stuff down.  The treatment plants have to handle it all.  Water treatment is known as a physical-chemical process.  A chemical, usually aluminum sulfate is added to the water to make bigger pieces out of the sometimes microscopic pieces that must be removed (bacteria, viruses, cysts, silt, etc.). 

Then, the water goes into a big tank where those bigger pieces tend to sink to the bottom.  Machinery of some sort scrapes the settled sludge out and sends it to be treated further. 

The settled water then goes to the filters where almost everything is removed.  Next step, chlorine to kill all the little nasties that make people sick.  Then it goes down the pipe to town. 

Sludge

Sludge

What about all the sludge?  Lots of things are in the lake water.  Birds, fish, even small organisms create waste products that can be dangerous as well as unpleasant (shit).  It is mostly water, but the solids have to be dealt with.  At Marston, it goes into a big underground tank and accumulates until it gets removed, dewatered, and hauled away for compost making. 

The tank is 20 feet deep, 50 feet wide, and about 150 feet long.  After accumulating for a year, the tank is about six feet deep with sludge.  Now, water plant sludge is not as nasty as wastewater sludge.  Some of it is chemical, clay minerals as the end product of all that aluminum sulfate.  But, there are lots of organics as well.  When they sit for much of a year in an airless environment, they decompose into stinky stuff.  That stinky stuff also gives off hydrogen sulfide gas (the rotten egg smell).  H2S and water make sulfuric acid, not good for lungs. 

To get rid of that huge gob of stuff, we had to get down there with fire hoses, air monitors, and gas masks.  Nasty work and a contrast with our normal routine of lab work, monitoring the computerized systems, and doing routine maintenance.  Dirty work with those hoses, but kind of fun as well. 

Belt Filter Press

Belt Filter Press

We used those hoses to carve sludge.  We would make channels, wash down walls of goo, bore holes, make it spatter our coworkers, and other exciting activities.  The whole process took a couple of days.  The sludge then went to a thickener eh are much of the water drained off the surface and the sludge drained out the bottom.  Then, on to the belt filter press.  That thing looks like a big printing press.  The sludge goes between two five foot wide belts that go over and under a succession of rollers that squeeze much of the water out.  The resulting cake goes up into big hoppers and then into trucks, and hauled to the compost making facility.  In the old days all that stuff went into the river.  Now, it is a useful product. Pretty cool, eh?

 

Weather

Climate Change

Climate Change

2013 Flood

There is currently a lot of controversy about climate change and whether humankind has a role in the warming trend.  While I think it is true that pouring huge amounts of sequestered carbon is the culprit, I don’t think it matters much for us here in Colorado and much of the west. 

We live in a land of extremes except for the rainy Pacific Northwest, but, they have their earthquakes and volcanos.  Here in Colorado, we dwell in a land of extremes.  The west is dry, it snows in the mountains, the Front Range is kind of a mix, and it is pretty dry in the east.  That varies from year to year.  It varies a lot.   

In the late nineteenth century it was a wet cycle in the eastern prairie, and the railroads made millions enticing settlers to buy their land and get rich farming.  The population in eastern Colorado peaked then and has been declining ever since.  The mountain ski areas have lots of snow some years and almost no snow other years.  The western desert country looks dry and desolate most of the time, but I have seen it bloom in a stunning variety of color.   

Then there are the floods, blizzards, and tornados, often followed by drought.  The one thing we can count on is change.  There are long term trends.  Most archeologists think one reason the ancestral Pueblo Indians left southwestern Colorado was a prolonged drought cycle.  Anyone who tries to raise dry land beans in that country can tell you not much has changed. 

2013 Flood

2013 Flood

Here along the base of the mountains we have the extremes as well. There was the drought of 2002, and the floods of 2013.  The mountains create an unusual weather pattern that stalls along the mountain front, bringing more moisture than the land can handle.  That is when lots of the mountains wash out into the flat country.  It has been going on for more than sixty million years.  The gravel in the Platte River in Nebraska is Rocky Mountain gravel.  Some of the Louisiana mud is Long’s peak mud.   

Some climate models say climate change is going to dry Colorado out, other models say it will be wetter.  My money is on more extreme weather.  Longer, more violent wet periods and long droughts.  Look for more frequent floods, not the thirty or forty year cycle we have had since the first European-American settlers and miners arrived.  Think about the tornados and hailstorms recently.   

I like the extremes.  We have our regular four seasons here but the winters are milder than in Iowa.  It can get hot but there are few days over one hundred degrees, but not like southeastern Utah.  I think that may change, hotter in the summer.  I don’t think the winters will be colder.  I can remember forty below in Boulder when I was flunking out of CU.  Twenty below seems to be more the cold winter norm now.  What I do not like is the hailstorms.  I don’t think the insurance companies like them much either.  Homeowners insurance costs keep rising.  That hail is hard on the garden as well. We had only one tomato plant survive last year. 

One of the big impacts of climate change will be on water supplies.  The amount of precipitation may not change, but if it is warmer, the snowpacks will not last as long in the spring.  That means more spring floods and a shorter runoff period, which will impact water storage.  That could be bad news for the populated Front Range.  People keep coming, but there will not be more water, and a lot of the big spring runoff will go out of the state.  That will be good for the Sandhill Cranes in Nebraska, but bad for Parker and Highlands ranch. 

I spent a long time in the water business, and it always disturbed me watching all that high quality drinking water being used to attempt to replicate Surrey or Connecticut foliage in the Great American Desert.   All that bluegrass will have to go. The urban forest will have more drought-hardy trees.  Denver Water’s customers have done a good job of conserving since the big drought of 2002, but the bluegrass model of landscaping continues.  In Denver, daily water consumption is about 110 million gallons per day in winter.  I the hot part of summer, it’s over 400 million gallons per day, most of it run out onto the ground. 

At our house, we have significantly reduced the size of our lawn, but we still have a lot of crabgrass.  It should be buffalo grass and blue grama, both native drought-resistant grasses.  They don’t stay green all summer, so we are stalling and paying the water bill.  Marijuana legalization is bringing lots of people to Colorado, and the economy is booming.  Those people use water, and lots of water is used growing the stuff.  One of the unintended consequences of legalizing pot is increased water consumption. 

Myself, I am not too concerned about climate change for myself.  After all I am 73 years old and don’t live on the coast.  Long term change is a reality, but as John Maynard Keynes said, “In the long range we are all dead”.

 

More On Flint Water

Flint Water

Flint Water

The tragedy of Flint, Michigan water continues.  Most people in our country take water for granted.  Turn the handle and clean, safe water comes out.  There is a bill to pay every quarter or month, but it is not very expensive.  If you are having paying, the water provider will work with you. 

When a Flint resident turns the handle, red, turbid water high in lead comes out.  It is not safe to drink and is dangerous for bathing and dishwashing.  When it is water bill time, Flint has the highest water rates in the country.  People are paying a lot of money to damage their brains. 

There was a Legionnaires Disease outbreak which killed nine people and sickened many others.   Legionnaires Disease is waterborne, usually from the aerosol from showers in buildings  using a recirculating warm water system using cooling towers or rooftop storage tanks.  The bacterium is often present in drinking water along with other bacteria and viruses in low numbers.  

Disinfection in water treatment is intended to kill pathogenic organisms in the water.  It does not sterilize the water.  Given proper conditions, those organisms can multiply enough to pose a public health problem.     The big ones are the cooling towers and storage tanks.  Another potential source are the rusty accumulations called tubercles in old cast iron pipes.  This is usually not a big problem because the bacteria are contained in the tubercles.   

Water Main Tubercles

Water Main Tubercles

When the water chemistry changes, making the water more corrosive, the tubercles break down, making red water and releasing the accumulated pathogens.  The water leaving the treatment plant is safe, but corrosive conditions in the distribution system release lead from old lead service lines running to houses that have lost their protective coating;  and pathogens are released from tubercules breaking down in the water mains. 

The potable water industry is highly regulated.  The utility itself is mandated to treat and test the water to insure its safety.  This includes testing water from individual taps in the distribution system.  County health departments also regularly test drinking water.  State Health Departments are also equipped to monitor water quality, although normally they rely on reports from the providers.  All this is overseen by EPA under the Safe Drinking Water Act.  The Centers For Disease Control also respond when unusual outbreaks occur. 

This is a lot of regulation and a lot of bureaucracy.  Usually the agencies work well together, as they share the same mission, assuring the water is safe.  The system broke down in Michigan when the state government assumed control of local cities facing a budget crisis.  The emphasis shifted from providing safe water to saving money.  The money savers were not water people and tended to ignore those reporting the unsafe water.  Instead of interagency cooperation, distrust arose.   

Flint is a city in crisis.  It once was a General Motors town, with lots of good paying jobs.  Many of those jobs are gone, the people who could afford to moved away.  Those left are poor and mostly black, with little political influence.  A toxic governmental situation created a toxic water situation.   

A main role of government is to protect the health and safety of the people.  It seems the Michigan state government avoided responsibility in order to save money.  There seems to be a large movement in our country to reduce the size of government.  This cost saving often comes at the expense of infrastructure.  As the roads, bridges, water and sewer systems, schools, police and fire departments decay, the quality of life of the citizens also decays.  All this did not seem to matter in Flint or the rest of Michigan, because the citizens affected tended to be poor and black.

Engineers

Tacoma Narrows Bridge Collapse, 1940. The engineer commited suicide.

Tacoma Narrows Bridge Collapse, 1940. The engineer commited suicide.

Engineers design things.  It may be lines of code for a computer application or the Golden Gate Bridge.  They have been at it for a long time.  Stonehenge, the pyramids, Petra, Roman roads, bridges, and aqueducts; all started as an idea in someone’s mind.  He then added the details to make the thing work.   

The details.  You can conceive of a bridge over a stream, but it has to be assembled, stay in one piece, support the loads going over it, and hold back the flood.  It would be nice if it looks good.  In addition it should not cost more than is necessary.  That is asking a lot, and in most cases the product is good at its job.  Think of it, are the stream banks solid rock or mud?  How deep is it, how do you support the bridge as it is being built?  What material to use?  Stone, wood, steel, iron?  What about the approaches?  How do you get the rainwater or snow off?   

Roman Aqueduct

Roman Aqueduct

There are lots of questions to be asked, and the answers have to be backed up by the numbers.    Stress, load, vibration, weather, wind, soil characteristics, and myriad other details have to be calculated.  Calculations can be avoided only if the thing is so overbuilt that little harm can come to it.  It is hard to do stress analysis with Roman numerals, thus things were overbuilt enough that they are still in service today.   

Currently, overbuilding is not an option due to cost considerations.  The thing has to do its job, last for its design life, be easy to work with, and not cost too much.  I spent thirty years in the water treatment business, and everything in the business has engineering behind it.  Most of the time everything works fine.  But, engineers make mistakes.  Walls collapse, processes don’t work, the power to a pump shorts out, the concrete leaks.  When you turn the new thing on, the software may not work.  All the engineering is critical, because the water has to go down the pipe to the customer, safely. 

For thirty years, I treated water using the engineers products.  Sometimes the product was faulty, but we had to make it work anyway.  The net result of this is that after working with the mistakes for so long, I have a deep, strong, profound anti-engineer bias.  In addition, engineers tend to be serious nerds.  They often are weak in social skills, and have difficulty communicating with others.  Lots of them know they are right, and refuse to listen to input from others who are not engineers.  Mistakes get perpetuated.  I must concede, however, that their stuff mostly works. 

The problems can be minor, like not putting the drains in the low spot to forgetting to account for water hammer in a piping system and pipes separate, flooding things.  A big problem we had to deal with was leaking concrete.  Denver Water has been pouring concrete since about 1900.  A lot of experience is in the specifications provided to the contractor building a new plant.  The contractor failed to follow those specifications and water poured out of the filter walls.  Water also came up through the floor from the channel bringing water into the plant.  It was necessary to take the plant out of service, drain the tanks, clean the walls, and coat them with epoxy.  That epoxy will not last as long as the concrete. 

There was one major exception to my dislike for engineers.  The plant where I worked had elements dating back to the 1920s as well as new construction.  Part of the new project was automating the entire plant.  There are lots of valves, motors, pumps, blowers, and other equipment, all interdependent.   

The software developers worked for months writing the programs to run everything.  There were twelve foot diameter valves, 400 horsepower motors, sensors monitoring every process, and it all had to work.

Water Plant Control Room With My Doppleganger

Water Plant Control Room With My Doppleganger

When we turned the plant on for the first time, it worked.  Everything did what it was supposed to.  This in a three hundred million gallons per day water plant.  In contrast, I started up a 10 MGD plant that just barely worked.  The biggest design flaw was a tank that was supposed to even out the water flow coming from the watershed to the water demand of the plant, which tended to fluctuate.  There were valves at the intake up the mountain, at the tank outlet, and at the plant.  The tank was too small to handle the fluctuations.  The plant was either starved for water or the tank was spilling.  There was software to sense tank level and flows, but it could not keep up.  The tank should have been at least twice the size.   

Don’t get me wrong, the work was challenging, interesting, and sometimes even fun.  There was enough variety to keep boredom at bay, and those engineering mistakes added to the challenge.  What the engineers did right, we just took for granted. 

Flint Water

Flint Water

Flint Water

After 30 years in the water industry, I thought I should give my take on the Flint, Michigan water crisis.  There is a misconception that the water from the Flint River the state emergency manager switched to is poisonous.  Not true.  Properly treated, the Flint River water is fine, and would meet all safe drinking water standards.   

The problem is that the water was not properly treated.  As it comes from the river, the water is corrosive and attacks metals in the distribution system pipes.  To be safe, it must be treated to make it less corrosive.  There are chemical additives (phosphates) that coat the pipes and prevent lead and copper from leaching into the water.  Here in Denver, lime or soda ash are added to raise the pH  of the water, making it less corrosive.  In addition, over time a thin film of calcium carbonate forms on the inside of the pipes, effectively sequestering the toxic metals. The phosphate chemicals do the same thing. 

How can you tell if your water is safe?  The corrosive water also attacks the rust that forms in an old system, such as in Denver or Flint.  If your water is red, it has rust, but also lead and copper.  The lead and copper come from the pipes, not the river.  The rust won’t hurt you, just stain your fixtures.  The lead comes from lead solder (now outlawed) used to join copper pipes and from lead pipes once used to bring water from the main into the house.  The lead service lines are slowly going away, but many houses have galvanized steel pipes into the house.  These are safe, but that steel pipe won’t bend to attach to the tap on the main, which is high on the pipe to keep sediment out of the service line.  The solution, a flexible lead loop bending from the tap to the service line.   

Corroded Pipe

Corroded Pipe

In Denver some older houses have lead service lines, but the lead loops are more common.  My entire neighborhood in South Denver with houses dating from the Victorian era to the 1940’s has lead loops.  Most of them are replaced when the old galvanized pipes rust out and there is a leak.  Our house has a copper service line now.  Several houses on the block have had their old service lines replaced since we have lived there.  Look where the water line comes into your house.  If it is copper, you are OK.  Flint has the same situation. 

Aggressive water leaches lead and copper out of the pipes and renders the water toxic.  Lead is the most dangerous, as it is a neurotoxin especially dangerous for developing fetuses and young children.  Copper is also toxic, but copper pipes are more resistant to corrosion than lead. 

If you have red water in your house, it is possibly dangerous and needs to be tested.  The Flint water is not just red, it’s red mud.   Before the Safe Drinking Water Act, many small water systems had aggressive water.  As a kid, I watched red water flow into our bathtub, especially in the spring, when the water was mostly runoff.  Maybe that is why I am nuts, as well as the rest of us from Fruita.

How did this happen in Flint?  Flint has a treatment plant, but was using water from Detroit which has good corrosion control.  Flint has plans to switch from the Flint River to Lake Huron  as their water source.  Lake Huron water is higher quality than river water, making it less expensive to treat.  Detroit water is from Lake Huron.  The Michigan emergency manager for Flint ordered the switch to river water to save money.   

Flint is broke.  The demise of much of the U.S. Auto industry hit Flint hard, a General Motors town.  The result, white flight, leaving a population mostly poor and black.  The city couldn’t pay its bills and the state took over with a team appointed by the Governor.  Here is the root of the problem.  The federal Safe Drinking Water Act establishes standards for drinking water.  The law gives the states the option to administer the law, usually by the Health Department or the Environmental Quality Department.   

So, the State government is running the Flint government and water treatment process and is also charged with insuring the water is safe, a clear conflict of interest.  A wild card?  Racism.  Those poor black people did not have much political clout and were essentially ignored and belittled when they complained about their water.  It took a brave pediatrician seeing high lead levels in her patients to finally get action. 

Four governmental entities are involved.  The Flint city government was rendered superfluous when the state assumed control.  The federal EPA was passing the buck to the Michigan Environmental Quality Department and not doing due diligence in making sure the department was doing its job (the EPA administrator lost his job).  The state environmental quality regulators knew there was a problem, but were influenced by the Governor’s emergency management.  The result, a perfect bureaucratic storm, with the people of Flint as victims. 

The cost?  A public health crisis that will cost millions to fix.  It takes a long time for the calcium carbonate or phosphate coating to form in the pipes.  In the meantime the water is unsafe.  The people of Flint will have to be provided with bottled water for some time.  Lots of bureaucratic fingers are being pointed.  There is plenty of blame to go around.  Will anyone go to jail?  Probably not, even though there is now a special prosecutor.  If the local Flint city government had been simply subsidized by the state until it got its house in order, the whole thing could probably been avoided.  Instead the emergency managers put money ahead of the public health.     

Many conservatives want to reduce the size of government, and return to the nineteenth century, before there was water treatment and people died of waterborne disease.  Government built a system to protect public health.  If government does not have the money do do its job, the public health will suffer.  Do you want safe water?  Don’t move to Flint.