David Estwick – Minister of Water
Dr. Robert D. Lucas
Dun-Low lane
Bridgetown
Barbados, BB11157
Tel.246-426-6512
28th, January2018
The Editor
Barbados Underground
Bridgetown, Barbados
West Indies
Dear Sir/Madam,
A press conference was held on the 26th. January that sought to clear the air over the discrepancies in microbial findings and interpretation of the potable water quality on the south coast of Barbados. The Americans found that there were elevated counts of microorganisms (this was not refuted by the local authorities) and advised their citizens to boil the water before drinking it. The Barbados’ government position is that Salmonella, coliforms and E.coli (fecal indicator (FI) organisms) were not detected and therefore the potable water on the south coast complied with the World Health Organization’s (WHO) guidelines. The press conference was aired live on the Voice of Barbados (VOB), and it was admitted by the Barbados Water Authority (BWA) that it had increased the level of chlorine added to the potable water supply on the south coast of Barbados. It was disclosed by the Minister of Health, that he became particularly concerned when it was revealed by the Americans that the advisory affected the area where he lives among other areas (it appeared that he was only interested in saving his own hide).
The following is written in the public interest. Let me start by saying that the Americans are correct in the position that they have adopted and that the local authorities are skating on thin ice, as I will now show…
There are other fecal indicator organisms also recognized by WHO. These are fecal streptococci, Clostridium perfringens among others. What are of importance from a microbial aspect of the above disclosures are the elevated numbers of organisms detected and the increasing levels of chlorine being used. When added to water, chlorine forms chlorous acid, which is able to penetrate bacterial cell walls, and disrupts protein synthesis resulting in death. It also attacks organic matter and indeed this is one of the drawbacks when using chlorine based-disinfectants. In other words, the greater the organic matter load of water, the greater the amount of chlorine which has to be used to attain a specific disinfectant level Fecal matter is highly organic in nature and therefore it is correct for the local authorities to up the levels of chlorine used. The problem, however is that the exact amount of fecal matter seeping into the potable water cannot be ascertain plus the microorganisms continue to grow and multiply and therefore estimates have to be made. This is starkly revealed by the elevated counts obtained by the Americans. From the disclosure the following events have occurred. Note we are dealing with hard science not law, economics or political science.
1. There was a high level of organic matter present in the water (could be fecal in nature or derived from food processing operations) and most of the chlorine disinfectant was used up in reacting with it.
2. Microorganisms were present at what is known in microbiology at levels too numerous to count (TMC); and since microorganisms are organic in nature, the disinfectant was not present at concentrations adequate to destroy all of them.
3. A combination of one and two occurred.
There is a risk associated with the use of chlorine as a disinfectant at high concentrations. At 200 parts per million (ppm) there is no carcinogenic risk associated with its use. At 1000 ppm chlorine is carcinogenic. BWA must in the public interest state what levels of chlorine have been used in an effort to achieve safe potable water.
Increasing levels of disinfectants increase the selective pressure on microorganisms and can result in pathogenic genes being passed from pathogenic organisms to non-pathogenic ones creating unwanted problems.
In any event, elevated levels of microorganisms indicate that something is wrong and the absence of the presence of fecal indicators does not preclude their presence at some time prior to the testing. The local authorities should therefore advise citizens in the affected areas to boil their drinking water, given that at the same press conference, the BWA admitted that the situation was getting worse.
The local authorities have been keeping a lot of noise about the gastroenteritis outbreak not being associated with the sewerage problem. They have not demonstrated the following:
Koch’s Postulates
Four criteria that were established by Robert Koch to identify the causative agent of a particular disease, these include:
-
the microorganism or other pathogen must be present in all cases of the disease
-
the pathogen can be isolated from the diseased host and grown in pure culture
-
the pathogen from the pure culture must cause the disease when inoculated into a healthy, susceptible laboratory animal
-
the pathogen must be reisolated from the new host and shown to be the same as the originally inoculated pathogen
Have the authorities grown the suspected causative viral agent in cell culture or have they used a DNA probe to substantiate their claim? Proof must be presented.
From food safety aspects, establishment dealing in food in the area affected should not have a say in whether or not to open or close their shops. Under the hazard analysis critical control (HACCP) system, which is considered the Holy Grail designation for food establishment, there are certain prerequisites, which must be met. These are sanitary standard operating procedures (SSOP’s) and current good manufacturing practices (cGMP). Absence of filth and obnoxious smells fall under these prerequisite conditions. Since currently, in the affected area these conditions are not being met, all such establishment should be closed by law. I train members of the Environmental Health Department at the Barbados Community College (BCC). The last time one of my students closed down a food establishment I wrote about it and the print media would not publish the article. It was published online and I was fired and actually received a letter from a prominent attorney giving me two-weeks to retract the article or be sued for libel. I ignored the joker. Last year I was at BCC teaching the students again. Most likely I will be fired again for writing this, which is neither here nor there with me.
Robert D. Lucas, PH.D.
Food Biotechnologist.
@Well Well & Cut N’ Paste At Your Service January 29, 2018 at 9:47 PM “BTW…Dr. Simple…they bite your face too ya know…how ya will cover that, I do not put spray on my face.”
Some mosquito repellents com as creams or lotions and can be used on the face, although you must still avoid getting them in the eyes or the mouth. I avoid the sprays because they tend to set off a sneezing fit.
Miller…one would say it is a good thing I did not post everything from CDC, only one little link set off people, the thing is, they asked for that link and actually accused me of mischief….
….imagine if I had posted the remainder of the information, therefore, I have learned today to let people do their own research, it is better for them..
In Barbados I always boil and filter my water. I found there is too much chlorine in it. At the house I stay at, we have bed nets, screens and I use spray. However, I got zika two years ago. The mosquitoes came in through the small bathroom window and when I came out of the shower and sat on the loo, they bit me around the ankles and behind my knees. I took down a friend from India, where they have every thing you can think of, and she caught dengue in Bim. When I got tested the lab found that I had had dengue in the past as they found antibodies. Barbados has some of everything. I will be on the island in March and staying in St. James, I will follow the same procedures and hopefully will not catch typhoid, even though all my vaccinations should be up to date from my Asian trip a few years ago.
Sewage is a problem in other places too!!
http://www.sun-sentinel.com/local/broward/fort-lauderdale/fl-sb-fort-lauderdale-sewer-crumbling-20170818-story.html
http://www.sun-sentinel.com/local/broward/fort-lauderdale/fl-sb-fort-lauderdale-infrastructure-20170509-story.html
… and in Miami
http://www.miamiherald.com/news/local/community/miami-dade/article176622811.html
What is your Rh point John?
I think geologically, Florida is perhaps close to the Barbados South Coast experience.
It is flat and not much elevated from sea level.
The same issues of tide exist.
The thing to bear in mind is that anything man made will in time decay and fall apart and requires constant maintenance.
Last time I was in Miami I saw major works on Biscayne Boulevard, ongoing it seems for a while as I remembered them from many times before.
Looks like sewage lines being replaced but, could be wrong.
Same issues of misspending of funds and lack of maintenance
Just that we have idiots who go out of their way to sweep problems under the rug and pretend they don’t exist.
Not possible with the scale of the system in various parts of Florida
The case of Miami suggests that alternative uses of wastewater are being sought and are still years away from implementation.
They are and will be creating confusion and dissent in the foreseeable future.
Until then, it goes into the sea!!
Not trying to minimize the South Coast problems … just to point out that they happen elsewhere in the world and the same reasons exist.
They are not soluble by the flick of a switch.
Thanks for your clarification John, had us worried for a minute.
Read the paper today are your politicians morons, dont look at us look over there, it happens there to is not an answer for people living through a crisis . A concise course of action… well circulated… time frames in place … and a realization that it cant be business as usual. Thats what gives people confidence in their govt and will allow them the time to fix it without be ravaged every day in the press. whats with kellman this US advisory is a good thing for barbados?????? what kind of warped thinking is that, the blp fed the numbers to the US embassey HUH.????? So three white countries have conspired with the opposition to take down the dlp.Nonsense
@ lawson
Last week David BU said he won’t be surprised if he saw such comments coming from the yard-fowls.
If Yugge could be committed to a mental institution for “dog talk,” Kellman should be likewise committed for “shiite talk.”
If wunnuh doan believe lawson read the following:
“However, despite the apparent common agreement that the US embassy had conducted its own tests, Kellman yesterday appeared to question the veracity of this, suggesting it was the Opposition Barbados Labour Party that had fed the embassy misinformation about the water quality.”
dpD
Couldn’t find anywhere else to put this.
Have you been following yesterday’s US news about what I think are potentially extremely serious developments re. the Trump minions’ war against the FBI designed to provide some cover against a looming impeachment?
Looks like the USA is now into the end game before it plunges into an existential crash from its world leadership through chaos in almost everything and surrogacy with Russia as Russia swings upward on the Pendulum.
One must hand it to Trump and his billionaire backers, led by Putin and assisted by the koches and mercerdes, for designing and implementing the various elements of a surrealistic plan that were always hiding in plain sight. The plan and its beautiful execution is now clear for all who think to see. The key is in the consistently disruptive choices that Trump was led to make for practically every significant post that he had to make and the now clear venality of the house and senate republicans. The only hope for the US to pull back from the brink now is a somewhat tainted judiciary but one that still has the teeth to right the US ship of state.
The next few weeks are going to be very interesting!
They can try to cover it up as much as they like, you cannot hide the stench of raw sewage, shit stinks and a plant takes years to fix….any part of the world.
Lawson….if you read both newspapers, you will see they have finally crashed the island, every infrastructure, every department, every area, the problems are now too numerous to mention or itemize, the list is too long, not even worth bothering to mention them singularly anymore…….
All that is left is the cleanup.
Watch for them cussing Marla Dukharan, she let them know how she feels today, they will not like that….lol..
….I will just watch them cause my tongue is swift.
@ Artax January 30, 2018 at 8:11 AM
We told BU long ago that the country was saddled with a pure bullshit DLP administration the behaviour of which would make EWB puke with shame from the shite that is being made of his legacy.
Can you imagine how Barbados would look if the stupid Bajans allow this set of deceitful lying pimps and goons to steal ‘back’ the government and rob the country of any chances of recovery?
OSA has to take some of the blame for what is playing out today.
He is well aware that this pack of wild boys are the ones running the country into the ground with their too heavy a load of incompetence reinforced with the ste(a)el of widespread corruption.
As he wisely pointed out: ‘Barbados is a good country but saddled with the worst government in its history’.
But what is he doing about it other than allowing himself to be consumed with vengeance and vindictiveness towards a ‘Mam’ who might have proven to be more ‘Man’ that he is today?
OSA, please come out of your period of convenient silence and stop being made to look like a scapegoat for the current administration blatant shortcomings.
We know you already pleaded ‘Mea Culpa’ for the past mistakes of your 14 year administration but to let MAM’s current cohort of BLP policy-makers be the fall guy for the DLP’s current mistakes is to swallow your bile of hate to deep in the guts of a man who wants to remembered as statesman who once came to the salvation of the country.
Are you prepared to take responsibility for the South coast fiasco or are you going to leave your closet of silence and speak your mind about this national disaster in the making that has the potential to destroy the opportunities you would wish for your children and grandchildren in a future Barbados
You have the BarbadosToday to air your views on this more than pressing national issues. Please don’t miss this final opportunity to right the wrong that has been made against your political and managerial competence.
@Are-We, outstanding clarity sir. OUTSTANDING!
I can only add: I hope the Republicans have carefully, VERY carefully thought this folly through.
You CANNOT decry and politicize your premier legal/police institutions as they are now doing and NOT expect long term pain.
As astute as you have shown here I know that you can connect the dots of for example the breakdown in our legal/police systems in Barbados, same in T&T and of course this current example in St Vincent.
In all cases short sighted political stupidity to defend acolytes creates a complete distrust of the systems and creates the I-want-mine-too mentality leading to pervasive corruption and dysfunction.
In closing, yes the next few weeks will be interesting. The republicans in the House have clearly shown they have no intent to hold the president accountable and are getting ahead of what now appears to be some explosive Mueller developments (note Nunes’ memo is released BUT the rebuttal Dem memo was voted ‘No for release; how more partisan and ridiculous can this be) …
… the US electorate in November WILL decide if pres Trump is impeached…if the Dems take control of the House then the people have spoken bluntly.
SIMILARLY Bajans will decide if Stuart is fit to be ‘put on trial’. If we resoundly dismiss his bunch of synchophant MPs then we too have spoken bluntly.
@lawson January 30, 2018 at 7:54 AM “whats with kellman this US advisory is a good thing for barbados?????? what kind of warped thinking is that, the blp fed the numbers to the US embassey HUH.????? So three white countries have conspired with the opposition to take down the dlp.Nonsense”
What can I say?
Except that some people are divergent thinkers?
Fruendel is getting a full on frontal attack on facebook…lol
@ David,
Barbados is up shit creek.
Barbados has suffered its fastest decline in foreign reserves in a year – US$16 million a month – regional economist Marla Dukharan warned yesterday.
http://www.nationnews.com/nationnews/news/124845/usd68m
The Defecation Liquid Party
“BWA signs multimillion solar deal.”
Am i missing something with this story? Is this the same organisation that is meant to be managing our sewage system?
http://www.nationnews.com/nationnews/news/124841/bwa-signs-multimillion-solar-deal
re You CANNOT decry and politicize your premier legal/police institutions as they are now doing and NOT expect long term pain.
Rather you must allow high level members of your “premier legal/police institutions’ TO BLATANTLY BREAK THE LAWS OF YOUR LAND, both overtly and covertly, AND THEN YOU MUST SIT AND LET THEM DO IT AND SAY ABSOLUTELY NOTHING. ah lie? yuh does read some shite pun BU though.
Somebody gwine soon declare that Marla Dukharan is persona non grata
The manholes are crying rivers again.
@Hants
De PM said they batting on a sticky wicket, something must be lost in translation he meant a “shitty” wicket.
Sargeant January 30, 2018 at 2:36 PM #
Somebody gwine soon declare that Marla Dukharan is persona non grata(Quote)
Why? For preaching 1960’s economic orthodoxy? Since the collapse of the fixed rate system in the 1970s, when the Smithsonian Agreement was signed, the mantra about foreign reserves has lost its impetus. After the sterling devaluation in 1967, the fixed exchange system became obviously vulnerable.
And after the devaluation of the dollar in 1971, there was no policy agreement to re-build a fixed rate system. I think we will all agree that the world has continued to move forward and upwards since the 1970s, 80s, 90s, naughties, and in fact, since 2008.
For some reason, which has nothing to do with the history of economic ideas, there is still a continuing consensus that the foreign reserves are at the heart of our macro-economic policy-making. It is not. Economists and policy-makers must get rid of their old university notes and update their knowledge. We need a national debate.
@ Sargeant,
De PM also say ” “So we have a problem, a problem not unlike what was going on in Toronto, Canada not too long ago.”
I respectfully suggest to De PM that the city of Toronto does not have shit coming up through manholes and flowing in the street.
However Toronto dumps shit into Lake Ontario when there is an over flow at the Sewerage treatment plants and they test the water and close the beaches when it is dangerous to swim.
http://app.toronto.ca/tpha/beaches.html
The FT Guy, seriously? Read a book recently? One single book January 30, 2018 at 3:19 PM #
What did he say?
The Board, Manager and Minister all want firing for thinking that a solar car port in Lakes Folly in 2018 makes sense. No wonder shiite floating along the South Coast.
According to a release from the Transport Board, prolong delays in service is as a result of only 62 units to service regular passengers and the school bus service.
“There will not be much relief during the coming weeks, as a number of buses undergo annual inspection.”
Some people in these jobs don’t think. Imagine the TB buying 100 buses…….. and licensing and insuring them on the same day. Obviously, the fleet would be 100 units short………..because they would be due for inspection on the same day.
Re: “Rather you must allow high level members of your “premier legal/police institutions’ TO BLATANTLY BREAK THE LAWS OF YOUR LAND, both overtly and covertly, AND THEN YOU MUST SIT AND LET THEM DO IT AND SAY ABSOLUTELY NOTHING. ah lie? yuh does read some shite pun BU though.”
When u have the chance please tell the blog which laws were blatantly broken. ….Please also advise what subseqyently the FBI did to (I presume) disadvantage the Pres of the US or candidate Trump.
When educated people conveniently fall into partisan mode to defend absolute indefensible action the society suffers.
It’s the same circumstances of partisan absurdity that allowed a CLICO mess to metastasize; that saw the dismissal on leave of the Dir of Insurance. Frankly similar partisan folly here facilitated the ALLEGED illegal surveillance of citizens by a former CofP directed by a minister.
Those same type of allegations are being made in Washington so Bajans who often steeupse when we discourse at length on US politics should open their eyes and see that our pols played the same game…just they used a very broad cudgel that brooked no dissent or political blowback.
Not so up north, tho.
Incidentally, The FBI has ALWAYS been a white-bred Republican leaning group of highly educated men. Think of who their main Hoover building is named after …or check the simple facts: 67% white males, less than 12% Blacks, Asians & Latinos and around 20% women.
During the campaign retired FBI folk were on TV often supporting Trump and giving updates based on leaks from SERVING special agents…yet we buy this crap that the FBI is out to get him.
The FBI does a reasonably good job of going after crooked people. Maybe that’s why he (and too Hillary) are so freaking afraid of their investigations.
It’s BS to believe that one deputy who may be Democratic leaning or a few other special agents talking loosely could comprehdnsively shift of direct an entire investigation…nonsense.
They would be leaks and others vociferously complaining.
Unlike how we operate in Bim these matters will be ventilated in US. So whereas we can send on leave our annoying officials and the matter dies a natural death…not a bit of that folly in this case.
@ Artax January 30, 2018 at 5:44 PM
Is this bus inspection an annual requirement? And if so, did similar days of commuter inconveneince occur in previous years and to be expected like clockwork by the traveling public?
Artax, you know that what you are being told is just a load of bullshit.
We are not dealing with stocktaking at a supermarket.
The vast majority of the buses are just totally inoperable due to poor maintenance (like the south coast sewerage plant) and a non-existent bus replacement plan or programme because of the lack of funding from Central government.
I say again “Rather you must allow high level members of your “premier legal/police institutions’ TO BLATANTLY BREAK THE LAWS OF YOUR LAND, both overtly and covertly, AND THEN YOU MUST SIT AND LET THEM DO IT AND SAY ABSOLUTELY NOTHING. ah lie? yuh does read some shite pun BU though.”
I say also in the words of the legendary Fanny Fields “IF IT IS THERE …IT WILL REACT! IF IT AINT THERE…….IT CANT REACT.”
@Artax January 30, 2018 at 5:44 PM According to a release from the Transport Board, prolong delays in service is as a result of only 62 units to service regular passengers and the school bus service.
@Transport Board “There will not be much relief during the coming weeks, as a number of buses undergo annual inspection.”
Can’t they at least arrange annual inspection during the times when tens of thousands of school children are on vacation?
Or is that too much to ask?
David January 30, 2018 at 2:39 PM #
The manholes are crying rivers again.
++++++++++++++++++++
The Worthing Post Office is due to open tomorrow.
https://www.tide-forecast.com/locations/Bridgetown-Barbados/tides/latest
There was a high tide at 2:28 pm …. 0.89 metres.
If tide was anything to do with it, that might explain your observation.
It fell to -0.02 metres at 9:19 pm tonight.
Amazing to see how low it was … and far out on Sandy Beach …. tomorrow night at 10:04 it will also be extremely low … -0.03, lowest for the month.
However, tomorrow at 3:19pm it will be the highest for the month, 0.9 metres … Super Moon.
It looks like they let out water from the swamp this afternoon, the level was between 0.6 and 0.7 … they should probably have waited till 9 or so tonight with the extreme low tide and let it out then.
If tide is anything to do with it, the employees at Worthing are going to be met tomorrow afternoon with bubbling manholes on their first day back on the job.
We will see.
Just after 3 this afternoon the tide will be the highest for the year and for a while.
Just after 10 tonight, it will be the lowest for the year and for a while.
Worth passing through St. Lawrence Gap and looking through the window to the sea to appreciate the difference
Alternatively, go on the beach somewhere ….. my guess is Cattlewash will be amazing but Sandy Beach works as well.
The moonlight will be spectacular unless it is overcast.
Next Super Moon will be Erroll Barrow Day, next year so worth getting a peek today and tonight at the tide and the moon.
I came across this article on degradation of the German Sewage System.
Might be quite different from ours here as it has been in existence for 70 years but one of the mechanisms of decay makes interesting reading … H2SO4!!
Sulphuric Acid.
The need to budget large sums and manage the network is apparent.
Once we stepped into the era of a sewage system the need for improved accountability, management and planning came to the fore.
We missed the bus!!
https://www.irbnet.de/daten/iconda/CIB2045.pdf
… and if sulphuric acid is present, and it must be giving the stench, probably Hydrogen Sulphide, then CaCO3, limestone is going to be eroded much faster than by Carbonic Acid!!!
These guys better get this mess right or parts of Highway 7 we may very well watch collapse!!
Thanks John!
https://nextcity.org/daily/entry/water-conservation-problem-broken-sewer-pipes
@ John February 1, 2018 at 10:07 AM
Sir John, so you are ‘stubbornly’ warming to the thesis that the undermining of the road network on the South coast might be taking place and possibly putting the already over-laden utility poles at serious risk of falling over and creating a Bajan infrastructural 9/11?
Wouldn’t you agree with what your mother told you about ‘an ounce of prevention is worth a pound of cure’?
I addressed the idea a while back using the presence of Carbonic Acid to explain that it might be possible.
However, it may be that sulphuric acid is also present.
Water on its own won’t cause the dissolution of coral otherwise Highway 7 would have collapsed years ago!!
You know when some places brag about the secret ingredient they have in their recipe,….. now we know what it is.
https://nepis.epa.gov/Exe/ZyNET.exe/200048ZZ.txt?ZyActionD=ZyDocument&Client=EPA&Index=1991%20Thru%201994&Docs=&Query=&Time=&EndTime=&SearchMethod=1&TocRestrict=n&Toc=&TocEntry=&QField=&QFieldYear=&QFieldMonth=&QFieldDay=&UseQField=&IntQFieldOp=0&ExtQFieldOp=0&XmlQuery=&File=D%3A%5CZYFILES%5CINDEX%20DATA%5C91THRU94%5CTXT%5C00000001%5C200048ZZ.txt&User=ANONYMOUS&Password=anonymous&SortMethod=h%7C-&MaximumDocuments=1&FuzzyDegree=0&ImageQuality=r75g8/r75g8/x150y150g16/i425&Display=hpfr&DefSeekPage=x&SearchBack=ZyActionL&Back=ZyActionS&BackDesc=Results%20page&MaximumPages=1&ZyEntry=8&slide
Page 6 is worth looking at to understand how the highway can be undermined and sewage pipes become blocked.
If we have processes like these in an advanced state, there will be whole sections of the sewage system under highway 7 that will need to be replaced.
This is not a quick fix if such processes are advanced.
Listening to the minister describe 5 foot diameter concrete sections that are fractured sounds to me like this may be the cause.
The water table can get into the concrete casings and the tide will cause it to rise and fall, which I believe we have witnessed at some manholes.
We got a serious problem.
Big $$ may need to be spent …. again.
No party isn’t fixing this in under a year … but miracles do happen!!
We should eliminate the possibility that sub standard materials were used in the construction of the sewage system.
There are three possibilities if corrosion is the culprit.
First, the design engineers specified substandard materials
Second, the contractor cut corners
Third, which we automatically assume, the folks at the BWA were lapse on maintenance and the powers that bee and dee did not adequately fund the ongoing system maintenance.
Before we jump to the third alternative we should inquire into the first two.
In fact, I am surprised neither party has raised this issue given the licks they have been getting.
If we are at the IADB looking for finance is it to fix the problems or is it to replace sections of the system which have worn out.
It looks from cursory digging on the internet that sewage systems have a lifespan and in our case, it may have been shorter than it should have been.
Here is a report to Congress in 1991, before our system was built highlighting the issues in the US.
https://nepis.epa.gov/Exe/ZyNET.exe/00000L69.TXT?ZyActionD=ZyDocument&Client=EPA&Index=1991+Thru+1994&Docs=&Query=&Time=&EndTime=&SearchMethod=1&TocRestrict=n&Toc=&TocEntry=&QField=&QFieldYear=&QFieldMonth=&QFieldDay=&IntQFieldOp=0&ExtQFieldOp=0&XmlQuery=&File=D%3A%5Czyfiles%5CIndex%20Data%5C91thru94%5CTxt%5C00000000%5C00000L69.txt&User=ANONYMOUS&Password=anonymous&SortMethod=h%7C-&MaximumDocuments=1&FuzzyDegree=0&ImageQuality=r75g8/r75g8/x150y150g16/i425&Display=hpfr&DefSeekPage=x&SearchBack=ZyActionL&Back=ZyActionS&BackDesc=Results%20page&MaximumPages=1&ZyEntry=1&SeekPage=x&ZyPURL
Here was the situation in Los Angeles in 1991.
Most of the CSDLAC collection sewers, especially the large-diameter lines in the lower reaches of the tributary system, are constructed of reinforced concrete pipe with no protective coatings or liners. These large sewers generally range in size from 54 inches in diameter up to 144 inches in diameter. The oldest of these sewers have been in service for approximately 65 years.
At the time these sewers were designed, concerns existed about the possibility of
corrosion. To guard against this possibility, the earliest of the large sewers had vitrified
clay liner plates installed on the interior sides and crowns. However, sulfuric acid easily
penetrated the joints between the tiles and destroyed the grouting and cementitious
materials underneath. By the late 1930’s after approximately 10 years of service, enough
of the tiles had fallen off into the bottom of the pipes to create flow obstructions and
necessitate cleaning of the debris from these pipes.
Because of the problems experienced with the tile liners, CSDLAC looked for
another method to prevent corrosion damage. The Districts chose to design sewers to
induce sufficient wastewater velocities so that natural reaeration would minimize the
growth of the anaerobic slime layers on the submerged pipe walls where the sulfide
generating bacteria grow. Such natural reaeration forces would also help oxidize any
sulfide that did form in the wastewater, preventing its release to the sewer headspace as
hydrogen sulfide gas.
In the early 1950’s, concrete pipe manufacturers began to market internally lined
pipes to protect against hydrogen sulfide corrosion. However, at that time, little
information was available to document how well these plastic liners would remain
securely bonded to the concrete and provide effective protection. The lined pipe was
expensive when compared to regular, unlined pipe, and CSDLAC decided to rely on
high design velocities to control corrosion, rather than lined pipe. Consequently, during
the 1950’s and 1960’s, as the size of the collection system increased dramatically,
CSDLAC continued to install unprotected, reinforced concrete pipe for much of the
sewer system. Current County standards require lined concrete pipe in all new
installations to prevent corrosion.
The City of Albuquerque maintains approximately 1,400 miles of sewer which
serve approximately 450,000 people and transport an average of 49 million gallons per
day (mgd) of wastewater to the city’s treatment facility. Separate storm sewers are used
throughout most of the city, but some combined systems do exist.
Albuquerque experiences 90 to 100 collapses per year that are attributed to
hydrogen sulfide corrosion in its approximately 400 miles of 8-inch-diameter concrete
pipe. These collapses are mostly in residential areas, and each typically involves two to
four pipe sections (20 feet). The problem of pipe collapse is widespread in the city, but
seems concentrated in North Valley, an older part of town that bas the most concrete
pipe, and in pipe 40 to 60 years old. The rest of the collectors are mostly clay pipe.
Pingback: Local Biotechnologist Comments on American Advisory | Should Barbadians be Concerned About ELEVATED Levels of Bacteria in the Water? | Should Food Establishments on the South Coast be Closed by Government? — Barbados Underground – THE BIG BUCK HUN