Category: Clean your tanks


Ron Perrin Clean Water Tank Project elevator pitch, why I started this in about a minute!

Our Mission: To promote the safe inspection & cleaning of water storage tanks and towers with:  1) Publications, 2) Video projects, 3) Safety training and 4) Support research to explain the dangers hidden in tank sediment and the need to remove it from tanks.

Our fundraising efforts for this project will help fund education of safe water system practices for smaller at risk systems, like this one.  The purpose of our organization is to highlight the need for clean public water storage tanks.  Cleaning tanks is something that is often overlooked in smaller systems.

The need for training is real.  Again this week we found tanks that have not been cleaned in over a decade!  Tanks in many smaller systems simply fall through the cracks, going year after year, Out of Sight, Out of Mind, and there simply is not enough education on this subject.

Please take another minute to check out our blog and take our poll: Lower on the page at

http://www.ronperrincleanwatertankproject.org

We are a newly formed Tax Deductible 501 c3  corporation.

Please help us get this message out to the entire country!  DONATE NOW

 

This site is supported by Ron Perrin.  Since 1997 my company Ron Perrin Water Technologies has been a leader in underwater inspection and cleaning for the water utility industry. We offer underwater inspection and cleaning services to municipal water utilities so they do not need to drain water tanks or towers to inspect or clean them. Our city drinking water comes from surface waters (lakes, rivers or streams) or ground water (well water).  After the water is treated it is sent to the water storage tanks & towers where it waits to be used at your tap.  Over time sediment builds up in these tanks  the sediment can be a safe habitat for bacteria protozoa and even viruses.

Our cleaning service is performed by Commercial Divers(also called line air because they are breathing surface supplied air on an umbilical line). They wear dry suits that completely seal them in their own environment.  The diver is then washed down with a chlorine solution before entering the water supply.

Once inside the water tank or tower our diver can quickly remove the accumulated sediment from the interior floor of the tank. Removing the habitat that can hide bacteria and other contamnants makes the water safer to drink and safes the utility money by reducing chlorine cost.   because the contaminants are no longer growing and depleting the chlorine reserves.

There is a link between many water contamination outbreaks and poorly ran water systems. The link is dirty water tanks. After water is treated at water plants it is stored in water tanks and towers near your home or business waiting to be used. Failure to properly inspect and clean these facilities is a big part of the problem in many systems. Legionnaires Outbreaks simply do not happen at well maintained systems that properly inspect and clean their water storage tanks. Over time sediment builds up on the floor of tanks and towers that store drinking water. Layers of sediment on the floor of the tank can become a safe habitat for bacteria, protozoa and even viruses! The contaminants grow under the sediment until they overtake the disinfectant chemicals. This is not rocket science it is basic housekeeping. Floors need to be kept clean, especially floors inside your drinking water tanks.

Potable Water Line Air divers equipped with surface to diver communications can remove sediment efficiently from water tanks and towers with a vacuum cleaning process.

Potable Water Line Air Diver

Potable Water Line Air Diver

Several inches of sediment may contain countless bacteria, protozoa or even viruses.  The AWWA recommends that tanks be cleaned every 3 to 5 years or as needed.  Keeping your tank floors clean is the best way to insure the health of your water system.  Photos- Ron Perrin Water Technologies http://www.ronperrin.com

IMG_2372

In November of 2013 the EPA published a report on “The Importance of Water to the U.S. Economy”.

We are in the business of Inspecting and Cleaning potable water storage tanks and towers.  Saving potable water is the center point of our underwater tank inspections and in-service diver cleanings.  In this paper the EPA has drawn attention to how valuable our water supply really is as an essential part of our economy.

This is a must read for anyone who is in the business of water distribution. In fact, by the time you’re done with it you may agree this is a must read for everyone.

This report raises awareness of water’s importance to our national economic welfare.  The report highlights the economic importance of water and at the same time how hard that fact is to measure.   The report establishes some extraordinary facts . For example, “The U.S. Geological Survey (USGS) estimates that in 2005, water withdrawals from groundwater and surface water in the United States totaled approximately 410 billion gallons per day (BGD) (USGS, 2009).1 USGS reports withdrawals for eight water use categories: public supply; domestic self-supply; irrigation; livestock; aquaculture; industrial; mining (including oil and gas extraction); and thermoelectric power. Exhibit 1 shows the distribution of withdrawals in 2005 by category”.

Read the entire report here: “The Importance of Water to the U.S. Economy”.

If you need more information about saving water with underwater tank inspections or in-service diver cleanings for your potable water or fire prevention tanks, click “RON PERRIN WATER TECHNOLOGIES“, or call toll free: 888-481-1768.

Please share this post, or at least the link to:  “The Importance of Water to the U.S. Economy”.  The truth is that the EPA is very good at writing papers, but not so good at getting them read. This is a significantly important work that should become a sounding board for the entire country.

300.000 Gallon

300.000 Gallon

Sediment Being RemovedFrom 300,000 gallon drinking water tower.

Sediment Being Removed
From 300,000 gallon drinking water tower.

The water storage tanks and towers you see around your city or town are the last stop for drinking water on its way to your tap.  By the time the water enters the storage tank it has been processed through filter media or other forms of treatment to meet EPA standards. Over years of service, sediment builds up in water storage tanks and towers.  One particle at a time, from a half to three inches is a common amount of build up over several years.  This sediment that gathers on the bottom of the tank floor is seldom thought about.  Out of sight and out of mind, it lays undisturbed becoming a welcoming habitat for bacteria, protozoa and even viruses. . .

Sediment under Microscope

Sediment under Microscope

A close up of the sediment under a 4x microscope did not reveal any moving contaminates, but still, nothing you would want to drink. . . . .

Sediment water under a 40X microscope

Sediment water under a 40X microscope

. . . However, under a 40x microscope we could see the movement of microorganisms.  Removing the sediment from the floor of the tank removed the habitat that these microbes were able to live in.  Now chlorine will keep the drinking water fresh and pure, free from bacteria and other living contaminants. . . . . This is raw video of what we found with our 40X electronic microscope.   For more information on water tank cleaning visit my commercial web site at http://www.ronperrin.com One of our divers thought he had something important to say from the top of a water storage tank we were cleaning.  He made this video and put it online.  A little rough, a little crude, but he makes a good point. If you would like a quote on cleaning or inspecting a water storage tank or tower please call us toll free at 888-481-1768. Check us out on FACEBOOK and LINKED IN and share this site with your friends!

Do you need a Potable water tank or tower inspected?

Our inspection methods offer the most information for the least cost,  all of our inspection methods include an underwater DVD allowing you to see what is in your storage tanks.  Remote video camera, ROV or potable water diver we have a method for every budget.

Call us toll free at 888-481-1768 or simply fill out the form below:

All water tanks accumulate sediment over time.  The soft sediment in the floor of water tanks and towers becomes a safe habitat for bacteria, protozoa and even VIRUSES!   *** see reference at bottom of the page.

Out of sight out of mind-

No one thinks about the sediment.   Most have no idea it is even there.

Not the water utility administrators, not the mayor not the elected city council members.  Many times elected officials vote to clean or  repaint the exterior of a water tower and never consider the inside condition.  The popular view is that Pure Treated drinking water is pumped into the water storage tank or tower where it is held, until the end user opens a tap at their kitchen sink and gets a glass of crystal clean water.

The Truth-

All water distribution systems accumulate sediment in tanks over time.

The water is often tested daily, if the chlorine residual goes down – operators do not ask why, they just add more chlorine, over time the additional chlorine breaks down and itself becomes a contaminate in the tank that can cause cancer.   *** See References below

Instead of constantly adding more and more treatment chemicals, simply cleaning the sediment from the floor of the tanks is the solution.

A countless number of biological contaminates can use the sediment in the floor of water tanks and towers to get a foot hold in a municipal drinking water system and grow into a real health concern.  Why should we care what is on the bottom of a water storage tank?

We drink off the bottom of water storage tanks!  Of course like many things the adverse health effects are unequally distributed to poor communities where drinking store bought bottled water is not a given, It is also these communities who have underfunded water systems that suffer from lack of maintenance.

Many utility systems that can afford inspection and cleaning of their systems simply do not allocate the funds for it because there are no regulations requiring them to do so.

In Texas yearly inspections of water storage tanks and towers are required.

Tanks get inspected in Texas.  The problem in this state is there is no rule or regulation requiring tanks to be cleaned. So while thanks get inspected every year,  most are seldom if  ever cleaned.

The AWWA (American Water Works Association)  recommends that water storage tanks be cleaned every 3 to 5 years or as needed.  The EPA has published multiple white papers about contamination public water systems and the importance to keep tanks free of sediment.

Few ever read EPA white papers and AWWA recommendations are largely ignored when there are no rules or regulations backing them up.

Of course there is always someone who is doing the right thing out there, just because it is the right thing to do.  In this case that would be the City of Arlington, Texas.

According to surveys conducted by the Environmental Working Group, Arlington, Texas has The best water in the United States, probably making it the best water in the world.  Arlington is located in the middle of the DFW metroplex getting its water from the same source as 50 other systems.   The water is treated in two water plants using similar treatment chemicals and methods as surrounding systems.

What sets them apart?  For the past 18 years But they  have made a commitment to keep their tanks clean,  Every year a Potable Water Dive crew is contracted to vacuum the tanks clean while they remain full of treated drinking water.    The divers literarily clean dust from the floor of water storage tanks, while surrounding cities allow multiple inches to accumulate before cleaning.

Too many water utilities in this country have no idea how much sediment if  any  is in the floor of their water storage tanks because they have never hired an inspection crew with underwater cameras to check it out.  It is never thought of so they stay caught in the cycle of adding more and more treatment chemicals when contamination is detected.

Lack of regulations in this overlooked undervalued part of our infrastructure is needlessly putting millions of people at risk for illness, cancer and even death.  When the solution is as simple as cleaning the floor of a storage area.  It just so happens that this area stores water, and it is often 150 foot or more up in the air.

The City of Arlington has proven the effectiveness of keeping water storage tanks clean,

According to the research I did for my book “Inspecting and Cleaning Potable Water Storage”  the majority of states do not have regulations requiring inspection or cleaning.

Do you think the EPA should require tanks to be Cleaned?

Take the poll :     CLICK HERE AND TAKE THE POLL AT THE BOTTOM OF THIS BLOG

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Visit http://www.ronperrin.com

This is a vastly complicated subject, that can be pulled down to three very simple terms.

  1. If you have a water storage tank or tower in your town there is sediment in it.
  2. Sediment bad,
  3. Remove Sediment and you remove the inorganic contaminates the habitat that organic contaminates can grow in.

See other videos and Vote Me Up! at http://current.com/users/ronperrin.htm

*** Quick Reference:

See:  Disinfection byproducts list at: http://water.epa.gov/drink/contaminants/index.cfm#Byproduc

Reference: Health Risk From Microbiological Growth and Biofilms in Drinking water Systems.  Published by  the EPA office of Water  June 17, 2002.

http://www.epa.gov/ogwdw/disinfection/tcr/pdfs/whitepaper_tcr_biofilms.pdf

QUOTE:

PAGE 26        G. Sediment Accumulation

Significant microbial activity may occur in accumulated sediment (USEPA, 1992b). Organic and inorganic sediments can also accumulate in low-flow areas of the distribution system, and enhance microbial activity by providing protection and nutrients (USEPA, 1992b). Biofilms that slough can accumulate in the periphery of distribution systems leading to sediment accumulation and the proliferation of some microorganisms (van der Kooij, 2000). Sediments may be an important source of nutrients in open finished water reservoirs, by accumulating slowly biodegrading materials which

are then broken down and released into the water column (LeChevallier, 1999b). The opportunities for biofilm development may be more abundant in storage tanks than in distribution system piping. Frequently, water is drawn from storage tanks only when water demand is high, such as during drought, fire flow, and flushing operations. This intermittent use results in prolonged storage times that may lead to increased sediment accumulation and lack of a disinfectant residual in the finished water storage vessel. Biological and aesthetic effects can be observed following the release of accumulated sediments from low flow areas of the distribution system (Geldreich, 1990).

Many studies have identified microbes in accumulated sediments, including both pathogens and non-pathogens. These include bacteria, viruses, protozoa, algae, fungi and invertebrates. Opportunistic pathogens that have been detected, and can multiply in sediments, include Legionella and mycobacteria (van der Kooij, 2000). Some primary pathogens can also survive for some time in sediments. Hepatitis A virus survived more than four months in sediments at both 5/C and 25/C (Sobsey et al., 1986). Other opportunistic pathogens found in sediments include Pseudomonas fluorescens

and Flavobacterium spp. (Berger et al., 1993). Sediments can also release nutrients into the water which stimulate biofilm growth downstream (LeChevallier, 1999b).

—————

Page 34      I. Proper Storage Vessel Management and Alteration

Proper storage vessel management and alteration, when necessary, can prevent contamination of the distribution system. Following TCR violations in 1996 in Washington D.C., one measure that proved effective in bringing the system back into compliance was the cleaning, inspection and disinfection of storage tanks and reservoirs (Clark, et al., 1999).

END QUOTE

A countless number of biological contaminants can use the sediment in the floor of water tanks and towers to get a foot hold in a municipal drinking water system and grow into a real health concern.  Why should we care what is on the bottom of a water storage tank?

We drink off the bottom of water storage tanks!  Of course like many things the adverse health effects are unequally distributed to poor communities where drinking store bought bottled water is not a given, It is also these communities who have underfunded water systems that suffer from lack of maintenance.

Many utility systems that can afford inspection and cleaning of their systems simply do not allocate the funds for it because there are no regulations requiring them to do so.

See potable water storage tank inspection and cleaning on this video.

This video shows how professional companies like “RON PERRIN WATER TECHNOLOGIES” using cutting edge equipment can make quick work out of inspecting and cleaning the most difficult water storage facilities.  The inspections can be performed with zero water loss or disruption in service.   Potable water divers can clean the floor of the facilities with minimal water loss providing a healthier storage area for municipal drinking water.  This makes a huge difference, a clean storage tank reduces the amount of treatment chemicals needed to meet current sanitary regulations.

Do you think the EPA should require Potable Water Storage tanks and towers to be cleaned?

Take the poll on this blog and be counted!

Link to the video

https://ronperrin.wordpress.com/2010/05/25/water-storage-tank-cleaning/

From my conversations with others in the industry this is what

their concerns are for storage tanks.

None of the tools that are outlined below have worked to get PWSs to

clean their tanks every 5 years.  Unfortunately, it comes down to the

personal preference of each PWS’s Manager whether the tank is cleaned on

a schedule recommended by guidance.

Some manager’s religiously clean their tanks every year, or every three years but for others, it never

occurs to them to clean their tanks.

This is unacceptable and can

sicken hundreds and cause fatalities.  Because nothing has worked, it is
vital for the protection of public health to create a regulatory (not
guidance) back stop that any system that has not cleaned and inspected
their storage tanks in the last 5 years would incur a violation.  This
is not a burden to those PWSs that have done what is right and followed
guidance but it does provide equal public health protection for those
who have not followed guidance.  We need to ask ourselves, where will
the next waterborne disease outbreak, like Alamosa occur?   In Alamosa,
one person died and 1300 others were sickened in a waterborne disease
outbreak that was caused due to neglect of their storage tanks – this
was completely preventable.  This person died needlessly.  Create a
regulatory backstop to prevent waterborne disease outbreaks from ever
occurring from such a preventable cause.

AWWA guidance and EPA whitepapers do not work to get PWSs to clean their
tanks every 5 years!

AWWA Manual M42 recommends tanks be drained, inspected and cleaned at
least every 3 years.  This same recommendation is reflected in EPA’s
Whitepaper on Finished Water Storage Tanks.  Kirmeyer, one of the
industry’s most  knowledgeable persons on storage tanks and water
quality, recommends tanks be drained, cleaned and have a comprehensive
inspection every 3  to 5 years.  These recommendations are ignored and
unknown to most PWSs.  They are recommendations, they are nice to do and
as a consequence, tanks are not cleaned and inspected and that’s why we
continue to find feet of sediment inside of tanks.  They don’t realize
the public health significance that sediment and holes large enough to
allow birds, rodents and insects into their tanks can have, it can lead
to waterborne disease outbreaks.  Salmonella can last for months in a
wet environment.  Clearly guidance does not work to get PWSs to clean
their tanks every 5 years.  We need a regulatory backstop to get PWSs to
do what is right for public health protection.  This does not need to be
delayed to study this to death, this is one of the most simple and
practical ways to protect public health.

None of the 50 states use their Significant Deficiency authority in
sanitary surveys for ground or surface water to clean their tanks every
5 years

None of the states have “not cleaning and inspecting their tank within
the last 5 years” as an item on their list of significant deficiencies.
The reason is States don’t realize the public health significance of
sediment buildup and/or the significance of breaches to a storage tank.
That is why cleaning and inspection is not on State’s significant
deficiency lists for sanitary surveys.  When you have both sediment
buildup and breaches, that is a fatal combination, and what causes
waterborne disease outbreaks like in Alamosa, Colorado.  One person died
from this Salmonella waterborne disease outbreak in Alamosa, he died,
from something that is totally and completely preventable.  There is a
class action lawsuit ongoing at this time.   You may justly ask why
aren’t we having waterborne outbreaks at more systems?  Because along
with sediment buildup and holes you need an event that would scour this
disease laden sediment into the distribution system.  Unfortunately,
that event that would awake this sleeping giant of a public health
concern is uncontrolled (e.g., fire flow, poor operation, power outages,
etc.) and that is completely unpredictable.  Gideon, Missouri had holes
that allowed salmonella contaminated bird feces into their tank but, it
was not until they underwent a flushing program that accidentally
drained their tank and flushed contaminated sediment into their
distribution system that the outbreak occurred.  This series of events
that led to hundreds of illnesses and 7 deaths stands ready to occur
again at hundreds of PWSs across the country.  EPA you have given the
drinking water industry a tremendous opportunity to prevent hundreds of
serious illnesses and fatalities from occurring from something the
industry already recognizes is vital to perform by creating a regulatory
backstop.  But, and I can not say this strongly enough, if you are
relying on significant deficiencies to achieve this goal it is not and
will not work unless there is a regulatory back stop.

State regulations that require PWSs to inspect their tanks only do not
work to get PWSs to clean their tanks every 5 years!

In the State of Texas where they have regulations that require PWSs to
have yearly inspections do not clean their tanks even when provided
overwhelming video and picture evidence of the sediment buildup.  They
don’t clean their tanks because they are not required to.  It is
impossible to inspect the floor of a tank when the sediment is not
removed.  The State of Wisconsin has recommendations for inspection
every 5 years, yet in the City of Brookfield two tanks were last cleaned
at a frequency of 7 years with 4 to 12 inches of sediment and another at
a 15 year frequency with 28 inches of sediment.     Clearly regulations
and recommendations to inspect only do not work to get PWSs to clean
their tanks every 5 years.  We need a regulatory backstop to get PWSs to
do what is right for public health protection.

State recommendations to inspect and clean their tanks do not work to
clean tanks every 5 years

Recommendations are largely ignored by PWSs.  Actually it’s much worse,
PWSs don’t even know these recommendations exist.  For example in the
State of Minnesota they had recommendations that stated ” All water
storage tanks should be inspected, cleaned and disinfected on an annual
basis.  Cleaning and disinfection should take place more frequently when
there have been identified water quality issues”.  The City of Moorhead,
one of the largest PWSs in the State, was unaware of any such
recommendation.  Recommendations to inspect and clean do not work to get
PWS to clean their tanks every 5 years.  We need a regulatory backstop
to get PWSs to do what is right for public health protection.

Protect public health over politics

Many agencies purporting to protect small systems (e.g., Rural Water,
RCAP, etc.) from the high costs of regulations are the very same systems
with the highest levels of sediment and most significant holes in their
storage tanks.  Many of these small systems can clean their tanks by
themselves with their own staff and fire hoses.  If these agencies were
truly helping these systems they should be assisting them to comply with
industry guidance of cleaning their tanks every 3 years.  If this were
the case such agencies would be able to say don’t worry about a
regulation to inspect and clean your tank it will never apply to you
because we ensure your tank in cleaned every 3 years.   The cost of a
cleaning a storage tank does not compare to the cost of a waterborne
disease outbreak and defending yourself from class action lawsuits.

People are concerned about their water quality.

By Ron Perrin            (c) 2010 all rights reserved

Cleaning water storage tanks is a positive action to address this problem.  While a few states require water storage tanks to be inspected only Florida requires tanks to be cleaned at this time.  The few states that do require tanks to be cleaned are content with the outdated AWWA methods of draining the facility, putting an inspector inside to check for structural soundness, and paint conditions, few inspectors pay a lot of attention to the sediment on the floor.  The tank or tower is then decontaminated by super chlorinating the water as it is filled.  That water is dumped, and replaced with fresh water that is tested before the tanks returns to service.  This method that has been in place for over 25 years and is a good way to disinfect any contamination an inspector may have introduced into the tank.  It will also kill a majority if not all of the bacteria and viruses that may be on the interior walls or on the surface of the sediment in the floor of the facility.

This method is NOT CLEANING the tank.  You can inspect & disinfect the water storage tank or tower and NEVER CLEAN IT.

If there are colonies of bacteria in and under the sediment before this process many will survive the disinfection process using the sediment for cover.  Protozoa like crypto can even survive the decontamination process on the surface of the sediment.  It has been proven that the only effective way to rid a water storage facility of crypto is physical removal.   What this decontamination procedure will do is return the tank to a condition that will pass a water quality check, while problems continue to grow in the sediment.

Most water storage tanks & towers are not designed to be cleaned.   The water drained goes directly into the water system.  There is not a “DRAIN PIPE” or “Wash Out Port” on most water storage tanks or towers.

The engineers that designed most of the  the tanks & towers in service today never thought about needing to clean them.  The thinking was this- It is storing perfectly clean and treated water in a closed system from the water plant, the water will be in the tank until it goes to the tap and is used by the consumer.  How could it get dirty?

Since 1990 tanks have been routinely inspected by divers, ROV’s and remote underwater video cameras.  What we know for sure it that over time WATER STORAGE TANKS accumulate sediment.

When tanks are drained & inspected what appears to be 1/4 or 1/2″ of insignificant sediment on the floor of the tanks, may actually be two or three inches of semi-liquid habitat on the floor of the tank that can support & hide billions upon billions of contaminates.  Seen with underwater cameras while the tanks remain in service we are only now beginning to understand how much of a threat sediment on the floor of a potable water storage tank is to public health.   Many states without any inspection rules are allowing feet of sediment to accumulate.

Tank Cleaning Methods:

Some attempt to pressure wash the facilities.  Workers are sent up and into a water storage tower with pressure washers and told to clean the tank.  They see a big floor drain in the center and of course push everything into it.  There is no where else for it to go.  Every thing that is cleaned with a pressure washer is then pumped right back up into the tanks when the facility goes back into service.

From the drawing board tanks & towers need to be designed with clean out drains & clean out valves.  Regulators need to understand that the AWWA rules for inspecting and disinfecting water storage tanks are antiquated.  The State of Florida is the first to understand that regulations must be in place to CLEAN tanks at least once every five years, in addition tanks that are attached to a raw water source must be cleaned annually.

For More information on tank & tower cleaning visit http://www.ronperrin.com

Polluted Drinking Water

Water Storage Tower Being Cleaned

People are concerned about their drinking water, and they should be.

To properly clean most water storage tanks the sediment must be PUMPED out.  Removing the sediment to the yard of the facility is the only practical way that the tank is really cleaned.  A Potable Water Dive Crew using equipment that is purchased for and only used in potable water is a economical way to keep the facility clean.  Wearing dry suits that completely seal the diver in his own environment the diver can be washed down with a 200ppm chlorine solution.  This removes the need to “decontaminate” the entire tank after the inspection or cleaning.  The diver can then enter the facility and vacuum  ALL LOOSE sediment from the floor of the tank, completely removing any contaminate that may be using the sediment for cover.

This method leaves the tank much cleaner than pressure washing or the traditional bucket & shovel.  It also saves water, using only a fraction of the water lost draining then disinfecting the tank.  Saving the utility time and water results in a saving of utility funds while providing customers with cleaner drinking water.  When human health is a risk, the savings cannot even be calculated when you consider that some basic housekeeping may keep your utility from being next weeks headlines regarding contaminated drinking water.

Article by Chris Griffin ADEM, Posted on the Alabama Department of Environmental Management  web site.

Would you drink from a dirty water glass?

This is a great article that ask a great question.  It also points out that the Alabama Department of Environmental Management has certain recommendations about routine water tank and tower maintenance that include tank inspection at least once every five years.

But they have gotten it WRONG.  Alabama requires the tank to be inspected by draining and disinfecting the interior a minimum of once every five years.

What is wrong with that you ask?

Disinfecting is NOT CLEANING.  We are not all speaking the same language here.  Many say disinfecting assuming when that is done the tank will be clean.  This is not the case.  From the engineers who build water storage tanks down to the managers who run the systems there has been a major break in communications with what is actually in water storage facilities.

The tanks & towers are designed to be CLOSED SYSTEMS, they store the crystal clear clean water that comes from the water plant.  When Alabama DEM requires operators to drain & inspect the water storage tanks and then disinfect the interior, that disinfection process is to kill whatever contamination may have been introduced into the tank during the inspection.  Sediment that was on the floor of the facility before the inspection is there after the tank is disinfected and placed back into service.

Disinfecting is not Cleaning,  if you have contaminates like bacteria, protozoa or even viruses buried in the sediment before the disinfection the majority of them are going to be there after the disinfection.  The only way to remove them from the facility is to CLEAN the TANK.

Most tanks and water towers were not designed to be cleaned.  There are no handy cleaning ports to open up and wash things into.  It was assumed by the designing engineers  that only clean water would be stored in these facilities and there was no need.

The reality is that over time sediment accumulates on the floor of water storage tanks and towers.  They need to be Cleaned out, not looked at and disinfected.

Once sediment is de-watered a few inches of soft simi -liquid sediment can become 1/2 inch of hard clay like coating stuck on the floor of the tank.  An underwater inspection can offer more information about the facility without any disruption in service.   Divers deployed to clean the tank can remove everything that is loose in the floor of the facility and provide video documentation confirming the job was done and the floor is now clean.

Washing a tank out after draining it for an inspection is not a viable way to clean a tank.  For example on an elevated tower, where is the sediment being washed to?  We have seen many cases where it was washed down the center standpipe only to return when the facility is put back in service.

The other option is a bucket and shovel, where even the most dedicated crew can not get 100% of the sediment out.  The shovel is also hard on the painted surface of the floor.  Divers removing the sediment OUT of the facility and onto the yard of the tank is really the best option.  When you consider the  disruption in service, man hours and cost of water divers are also the most economical option to clean a water storage tank or tower.

This is a great article that ask a great question.  It also points out that the Alabama Department of Environmental Management has certain recommendations about routine water tank and tower maintenance that include tank inspection at least once every five years.

But they have gotten it WRONG.  Alabama requires the tank to be inspected by draining and disifecting the interior a minimum of once every five years.

What is wrong with that you ask?

Disinfecting is NOT CLEANING.  We are not all speaking the same language here.  Many say disinfecting assuming when that is done the tank will be clean.  This is not the case.  From the engineers who build water storage tanks down to the managers who run the systems there has been a major break in communications with what is actually in water storage facilities.

The tanks & towers are designed to be CLOSED SYSTEMS, they store the crystal clear clean water that comes from the water plant.  When Alabama DEM requires operators to drain & inspect the water storage tanks and then disinfect the interior, that disinfection process is to kill whatever contamination may have been introduced into the tank during the inspection.  Sediment that was on the floor of the facility before the inspection is there after the tank is disinfected and placed back into service.

Disinfecting is not Cleaning,  if you have contaminates like bacteria, protozoa or even viruses burried in the sediment before the disinfection the majority of them are going to be there after the disinfection.  The only way to remove them from the facility is to CLEAN the TANK.

Most tanks and water towers were not designed to be cleaned.  There are no handy cleaning ports to open up and wash things into.  It was assumed that only clean water would be stored in these facilities and there was no need.

The reality is that over time sediment accumilates on the floor of water storage tanks and towers.  They need to be Cleaned out, not looked at and disinfected.

Once sediment is de-watered a few inches of soft simi -liquid sediment can become 1/2 inch of hard clay like coating stuck on the floor of the tank.  An underwater inspection can offer more information about the facility without any disruption in service.   Divers deployed to clean the tank can remove everything that is loose in the floor of the facility and provide video documentation confirming the job was done and the floor is now clean.

Washing a tank out after draining it for an inspection is not a viable way to clean a tank.  For example on an elevated tower, where is the sediment being washed to?  We have seen many cases where it was washed down the center standpipe only to return when the facility is put back in service.

The other option is a bucket and shovel, where even the most dedicated crew can not get 100% of the sediment out.  The shovel is also hard on the painted surface of the floor.  Divers removing the sediment OUT of the facility and onto the yard of the tank is really the best option.  When you consider the  disruption in service, man hours and cost of water divers are also the most economical option to clean a water storage tank or tower.

Potable Water Diver in DRY SUIT

Sand & Sediment being pumped

Sand & Sediment being removed from a Potable Water Tank

If you have any more details about  rules for inspecting & cleaning water storage tanks in Alabama or any other state contact me-  Im always glad to share information.

Please check out the rest of our blog at www.ronperrin.us and visit my web site at www.ronperrin.com

By Ron Perrin   (c) Ron Perrin 2010 all rights reserved

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