Saturday, November 07, 2015

The Importance of Efficient Leachate Collection and Reliable Leachate Pumps

Leachate pumps are important to protect the environment from leachate escape into groundwater, from which it could get into water supplies. If a leachate pumping system is inadequate to remove all of the leachate over a period of time, modern landfills which are lined (sanitary landfills) begin to fill-up with liquid, the weight of the liquid puts a positive leakage (outward) pressure on the base lining of the landfill. This both increases the danger of a bottom liner failure, and produces a finite (low) outward liquid flow through the base liner, which although of very low permeability does allow some water to pass through.

Multiply that over the typically huge areas of modern landfills and the amount of flow and the consequential pollution in the water would be likely to be significant amount. That is why any fluid inside a landfill of more than a nominal 1 metre depth is a potential source of pollutant emissions.

It is well known that leachate collection systems and the pumps which drive flow through them and out for disposal can lose their flow capability through a variety of causes. Organic material can silt the pipes up, sand and stones may enter due to landfilling operations, and on occasions they may scale-up up quite rapidly with “calcite" which forms a rock-like deposit, which can be very hard to break-up and jet out of leachate pipes. When pipe flows reduce such that they put a sufficiently large back-pressure, the leachate pumps fail to remove enough of the collected liquid fluid leachate builds up within landfills.

If this is allowed to continue, leachate containment will eventually be lost. When that happens unsustainable leachate leakage will occur. Leachate will escape with potentially toxic effect, and even below the toxic level escape of leachate would have serious consequences on the environment. Leachate is heavily polluted and potentially contains a great many chemicals and micro-organisms (including pathogenic bacteria and billions of minute viruses).

To meet the demanding requirements of modern landfills many leachate pump manufacturers have grown up around the world over recent years to serve the industry with some of the world's most rugged pumps ever known.

In the paragraphs that follow we have listed a number of suppliers with an excerpt from their websites to help explain their leachate pump systems and services offered to the landfill industry:
"A wide variety of electric pump types are used, all must be suitably corrosion protected to a high standard, and non leachate compatible materials avoided. By far the most common are the explosion proof (ATEX zone rated) submersible large solids particle size passing “sewage” type pump types.
The types of electrical pumps used include progressive cavity borehole pumps, multistage submersible pumps, high head dual impeller multistage pumps, explosion proof pumps (inherently safe in explosive landfill gas mixtures).
The web site of specialists Viridian Systems gives a list of the types of electric pumps used in leachate pumping on their web site at:
Read more here.
The ATZ Leachate Extraction Pump is a simple, robust solution to landfill leachate problems... The ATZ Leachate Extraction Pump is a positive-displacement piston pump that can be retrofitted into the existing gas well infrastructure. The pump can also be used for condensate knock-out chambers, whether under pressure or vacuum. The pump’s mechanical linkage converts the rotary motion of the DC electric motor to a reciprocating motion of the piston at the foot of the pump. This piston assembly is highly tolerant to particulate matter common in landfill fluids. The pump is also available with a solar-powered drive system which eliminates the need for a source of electrical power at the gas well. Additionally, we also offer a manually operated drive option.
Read more here.
Pneumatic positive air displacement leachate pump for harsh liquids in the landfill, brownfield, petrochemical and remediation industries. AP2, AP3 and AP4.
Read more here.
The SRX is an air-powered pump used to extract leachate or gas condensate at variable rates equal to the well recharge. Pump flow rates are up to 9.5 gpm at temperatures up to 250°F.
Read more here.
It’s pretty common to find buildup inside landfill well casings caused by minerals found in typical landfill leachate. But when industrial sludge or industrial remediation waste is placed in a landfill, the buildup may be accelerated and intensified.
So what to do? The short version: If you are getting buildup and the leachate pH is within the range of 4-9, you may be able to get by with silt filters and Teflon®-coated floats, but if you have more drastic changes in pH, or temperatures above 160 °F, you’ll probably have to treat it with acid or bromides. When it’s neutralized, you can revert back to floats and silt filters.
Read more here.
EPG offers a variety of sump drainers, one of which is the SURE PUMP. The sump drainers are stainless steel construction, corrosion resistant, sealed unit with liquid flow drawn past motor for cooling. EPG offers the Sure Pump which offers an innovation that is patented and accurate for level sensing. This leachate pump is used by professionals worldwide. There are horizontal, vertical and TSP Submersible Sump Pump Drainers.
Read more here.
The main features of the SPP ACTIVE range are quality and simplicity. SPP leachate pumps are manufactured from 304 Stainless Steel. They work without any bubblers, external controller or bleeders, utilising a simple twin valve control within the pump to regulate air pressure, fluid collection and discharge.
For total fluid recovery, bottom and top loading pumps are available. For targeted LNAPL recovery, skimmers can be supplied with SPP2 or SPP3 ACTIVE pump bodies.
Read more here.
An alternative to leachate pumps is a unit known as an eductor, or ejector. This unit is positioned within and close to the base of the borehole. It is connected to a surface mounted pump which in turn controls up to ten individual eductors.
The advantages of units such as these are: firstly, they are lightweight and streamlined for use within relatively narrow boreholes, secondly, there are no moving parts and thirdly they are relatively inexpensive. Eductors operate by circulation of water within a semi-closed system through a venturi located within the body of the eductor. This creates a pressure differential within the bottom of theborehole and causes leachate to be sucked through the eductor to the surface.
Value-giving proven performance ... renowned air-powered, ATEX Zone 0 certified AutoPumps. The improvements extend the service lifetime of the pump and broaden the range of its applications in extreme environmental conditions in landfill and remediation. Bottom or top-fill, the 9.1cm diameter submersible pumps are from 70 cm to 131 cm long and offer a maximum flow of 26.5-69 l/m at depths of 76m with actuation levels from 39-113cm depending on model.
Read more here.
Integrated Environmental Technology installs and performs warranty work on a large range of landfill leachate pumps. Our pneumatic landfill leachate pumps are selected from reliable landfill pump suppliers to support our long-term fixed landfill leachate pump maintenance contracts that our clients cherish.
We also supply and service methane gas condensate pumps that are cost effective, certified, automatic and reliable. Since our methane gas condensate pumps are self-regulating, they require no external form of actuation.
Read more here.
The Megator self priming positive displacement sliding-shoe pump provides exceptional suction performance, versatility, and the ability to pump at constant capacity against heads to 246 ft (75m). It can run without harm during dry suction, is self compensating for wear, has a simple design with few working parts and single cover access. It might be said to resemble a reciprocating piston pump, and it has indeed all the well known merits of that type - powerful suction and self priming, constant capacity at varying heads, the ability to cope with rough conditions and to handle a great variety of liquids, viscous or free flowing, clean or dirty. Yet in its simplicity, compactness and even flow it more closely resembles the centrifugal pump. It therefore combines the advantageous features of both these two main pump types without their respective limitations.
Read more here.

Saturday, September 13, 2014

Old Landfill Leachate Pollution a Leachate System That Works and Money Running Out


In this summary of news stories, leachate pollution continues to produce headlines in the US, and this time it is an old landfill that seems to be producing contamination of a river.

Those that understand leachate will not be surprised that an old landfill continues to give leachate problems. Due to the low water infiltration rates of more recent landfill designs, it may take hundreds of years before most landfills even receive a rainwater "flushing" equal to a single bed depth of water. In order to wash through the majority of contaminants will take 10 to 100 bed depths of rainfall, so the public should think of that and keep a watch on all landfills for a long time after they have been closed and capped.
The report to which I refer can be accessed by following the link below:

Environmental watchdog reports old landfill leachate - Mid-Hudson News

"Mid-Hudson News: Environmental watchdog reports old landfill leachate. GOSHEN – Environmental watchdog Susan Cleaver of Goshen has discovered what she believes to be leachate from the Orange County Landfill in the Cheechunk Canal. She has reported it to state environmental officials and county leaders. Cleaver, who ..."
That's not the only news though, and some are much more positive. I particularly liked the item below:

Leachate treatment system works - West Central Tribune
"West Central TribuneLeachate treatment system worksWest Central TribuneAnd the process is more environmentally sound than the county's current system of trucking leachate to Willmar's wastewater treatment facility. On top of that, they said the technology will save the county $3 million over the next 20 years. The board ..."
Yes. I like to read about success. Why are we surprised that a leachate treatment system works...

The author does not say what the "filtering system" is but I guess it is a Reverse Osmosis (RO) Plant. If so, it is the same as any filter. Whatever is caught up on the filter has to go somewhere! So, RO might be "green", but what happens to the material that is left on the filter? Where soes that get treated. If it is sent back inot the landfill I really don't consider that to be green as it is just returning the pollutants to the same place it leaked from in the first place! The question then is just, how long before it comes out again?
Finally, we are back into bad news with a money problem. It looks as if the environment is in for a bashing if no money can be found to deal with this leachate in future. Maybe, we have come full circle here to the start of this article. So, often regulators and landfill operators just fail to understand just what a long-term problem landfill leachate can be...

Landfill broke; Money to treat leachate at NABORS runs out - Harrison Daily

"Landfill broke; Money to treat leachate at NABORS runs outHarrison DailyMelinda Caldwell, executive director of the Ozark Mountain Solid Waste District, said the day for which the Board of Directors has been preparing finally arrived: The district is out of money to operate NABORS Landfill. kAm%96 7:?2?4:2==J EC@F3=65 ..."

Wednesday, June 25, 2014

5 Deadly Sources of Water Pollution - Don't Read This It May Scare You...

What the government doesn't want you to know about Water Pollution!

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Landfills are not specifically shown in this infographic, but are a potentially significant contributor to most of the pollutants shown. They can be chemicals that seep [sip] into the soil (especially if the landfill is not lined) and if leachate gets into the rivers and streams around a landfill they may contribute to all the other categories depending on what has been tipped into the landfill.

So, leachate from unlined and uncapped landfills is a potentially large contributor to the pollution shown in the infographic. But, thankfully, most landfills in the industrialized world nowadays are capped over the top to stop as much rainfall entering them as possible and lined so that the leachate which is formed can always be pumped out and treated so that it does not cause pollution of the sort shown above.

If a large landfill is near you and it is not lined and capped and the leachate is not pumped out and treated responsibly before discharge, you should be worried when you read this...

Tuesday, April 29, 2014

Leachate Treatment in India

landfill leachate treatment - Traitement du lixiviat de l'enfouillissement

Image by Sustainable sanitation via Flickr

The continuing poor management of landfills in India is a disgrace, so it is no surprise that although we have seen evidence that there is growing interest in the scientific application of good leachate treatment practice in India, it would seldom be possible to apply it, given the unscientific way in which so called "landfills" (dumps?) are currently engineered and managed.

The following is an extract from an article on 24 April of this year (this month) on which I rest my case, since it is based upon the wealthy capital city of the nation:
Delhi government calls its three garbage dumps at Ghazipur, Okhla and Bhalswa landfills. In reality, they are far from what a landfill should be. These are monstrous trash mountains, including hazardous waste, leaching out toxic liquids and emanating noxious fumes. Thousands of scavenging birds swarm over them as they grow larger every day.

The situation could have been different had the corporations given more thought to managing them. Ask any waste picker who scavenges on these dump yards about why this waste could have been a treasure...
...there are hundreds of waste pickers who pick up whatever they can without using masks, gloves or any other protection. Some even tie a magnet to a long stick to pull up metal objects.
 Credits: Capital dumps a fortune at its landfills - Times of India
In my opinion the provision of proper waste disposal facilities should be on the very top of the agenda as any nation industrializes and becomes more wealthy. If India cannot devote just a small amount of it additional wealth which has been accruing at a historically uniquely rapid rate for more than the last ten years, then it is a failing state.

To deny pickers the ability to make a living can be an evil, but so many other nations (including many of lesser wealth) have found a way to recycle waste in a way that provides jobs for the local community without recourse to the life threatening and certainly extremely unhealthy practice of "picking".

At the same time, it has been possible to provide reliable leachate treatment and disposal once the landfills are properly managed and built in accordance with good sanitary landfill practices as have been acheived in the majority of nations around the world.

Providing successful leachate treatment plant designs in India, for the old existing dumps is an impossible task. That is because the prediction of leachate quality is rendered from scientific capability to a matter of guesswork by a lack of data and controls, and this is made even worse by India's monsoon climate which means that any leachate treatment plant needs to be able to run at almost no flow in the dry periods and very quickly at the start of each monsoon be able to treat it's maximum design flows.

As the most effective, and lowest cost forms of leachate treatment rely on biological processes and these cannot be quickly switched on therein lies another problem for leachate treatment in India.

Then finally, any leachate treatment plant designer for Indian landfills will discover that the water quality that the Indian government's own rules require the leachate to be treated to, are as strict, or require higher water quality after treatment, than even many authorities require in the wealthiest industrialized nations.

Unfortunately, waste management and especially landfill methods don't seem to get any better in India, despite increased wealth. They won't be able to do so, until the central Indian government revises the rules and makes them realistic, less strict but much better value for money, and appropriate to what the municipalities can afford to spend.

The 80/20 rule should be adopted, at least to start with for all future leachate treatment projects because by reducing the specifications for final water quality and using innovative solutions Indian landfill operators should be looking to spend 20% of the cost they are being quoted currently for leachate treatment plants for 80% of the treatment quality, and that treated quality would be good enough for the local rivers for the health of the rivers to which the leachate plants discharge, and for those using the water from them.

Saturday, April 26, 2014

Report on Leachate Management Solutions Offered in Recent Articles

Let's start this article about leachate management by going back to basics and defining what we mean by the term leachate, and the way I suggest that we do that is to refer to the recent post from ET Environmental which gives a clear definition for any one reading this page who is unsure:
When liquid passes through trash material, such as in a landfill, “leachate” is generated. Rainwater is the largest contributing factor of leachate, but natural decomposition and discarded chemicals also contribute Credits: Leachate: What is it? - ET Environmental

Leachate management is the planned operation of landfill sites in such a way as to avoid the production of leachate as far as practicable, and to drain, collect, treat as necessary, and dispose responsibly of the leachate which is not prevented.

So, now that leachate has been defined we look further around the web and find that there is a discussion of managing landfill leachate seepages (often called "breakouts" in the waste industry), below the final capping membrane at, as follows:
Leachate seeping out of landfill slopes is a common occurrence. Operators struggle to address leachate seeps and manage liquids reaching landfill boundaries. During dry spells, it takes less effort on the part of operators to control liquids on landfill surfaces, and seeps are therefore more manageable. But during periods with frequent storm events or in high-precipitation regions, landfill operators must work constantly on slopes to stop seeps or devise means to control liquids when they do ...Credits: The Use of Leachate Toe Drain Systems Can Deal with Seeps After ...

The authors must be referring to landfills in very wet climates, as such seeps should not normally occur when landfill cells are covered rapidly after filling to avoid the potential for vermin to breed, and for odor production, as required by sanitary landfill procedures (US), or the EU Landfill Directives and related regulations.

Rather than build temporary toe drain systems at substantial cost it is normally recognized to be better to plan the cellular construction of a landfill for smaller cells and to bring those cells up to completion at the surface of the landfill as quickly as possible. Capping and restoration of areas of the landfill prevents further rainfall ingress and that not only allows a permanent landfill gas extraction system to be installed as soon as possible for maximum landfill gas capture, but minimizes leachate production. That's the best form of leachate management there is, namely - make sure that the landfill produces as little as possible!

While browsing for leachate management solutions, we found our own website back in 2011/12, which contains some articles on the subject, namely:

The starting point in any discussion about UK/ EU leachate management techniques is to begin by stating the overriding rule upon which all landfills are operated, in compliance with the EU Landfill Directive. That is that as far ... Credits: Leachate Management Techniques | The Leachate Expert Website

However, perhaps the best page about leachate management is to be found on the leachate Wikipedia page.

Friday, April 25, 2014

Recent Leachate Problems And How To Cure Leachate Breakouts

There have recently been a number of articles on the web that help with solving many of the recent leachate problems which have been publicised.

The types of problems which landfill operators are experiencing have been exemplified in the following articles already this year:

1. Leachate Produced that must be Treated Before Disposal

The landfill site in Memelhakha in Thimphu has started producing leachate. Leachate ,the liquid produced by waste, is said to be poisonous as it contains toxic chemicals. Leachate can also contaminate the ground water and ... 
Credits: Memelhakha landfill starts producing toxic leachate | BBS

2. Leachate which Escapes a Watercourse Before It Can Be Collected and Treated for Safe Disposal

The following was reported on the Department of Environmental Quality's Riverbend Landfill website,  but don't bother looking online for information about the January leachate leak -- that information is no longer there.

Leachate release — On February 10, 2014, landfill personnel observed leachate escaping from the landfill’s northern boundary. Waste Management reported that this leachate reached a creek approximately 300 feet from the landfill.
This leachate was primarily liquid that had collected in the landfill’s gas extraction wells. To keep the extraction wells working properly, this leachate is routinely pumped from the wells to three 21,000-gallon storage tanks near the north side of the landfill. This leachate is kept separate from the majority of the landfill’s leachate, which is pumped to the onsite leachate pond.
This reason for this separation is that leachate associated with the gas extraction wells is more concentrated than the rest of the landfill leachate, and is therefore sent to a different offsite facility for treatment and disposal.
Tanker trucks that routinely haul this leachate to an offsite treatment plant were unable to get to the site because of heavy snow and icy roads.Flow of leachate from the landfill to the tanks was stopped because the tanks were full.
This is believed to be the reason leachate began seeping from the landfill. To prevent this problem in the future, Waste Management has connected these tanks to the pipeline leading to the onsite leachate storage pond.
 Credits: January Leachate Leak? - Stop The Dump Coalition - Blogger

3. Leachate Which Escapes Into the Ground and Creates a "Plume" of Pollution Below the Ground

The investigation was carried out to ascertain leachate plume generation and migration and its impact on the surrounding soil and the groundwater. 2D electrical resistivity imaging using Wenner array was used to delineate ... 

Credits: 2D Electrical Imaging Surveys for Leachate Plume Migration at an ...

Solutions And How To Cure Leachate Breakouts

The breakout of leachate both to the ground around and below a landfill can be prevented by good landfill lining design, and high quality construction of the liner with a high degree of construction quality control, preferably by an accredited independent organisation.

Find out more at

Tuesday, November 12, 2013

Building Work Starts on the World's Most Expensive Leachate Treatment Plant

Construction work has begun on the world's most expensive leachate treatment plant which at $27 million will be the most expensive ever built in the world to date. 

A number of plants are estimated to have been built at up to $15 million previously, but this one is significantly the most expensive in terms of the (assumed) capital cost, and it will only pre-treat the leachate which will then be discharged to the public sewer.
There will be an additional charge for that, levied by the Wastewater Treatment Works operator on top of the running costs for the leachate pre-treatment plant - but that cost pales into insignificance when compared with this level of investment.
We have found the following information on the web about the project:
JOHNSTON — The Rhode Island Resource Recovery Corporation (RIRRC) recently broke ground on a $27 million leachate pre-treatment plant. The new facility, which will be built on RIRRC property, will utilize green principles to create an energy-efficient system capable of properly treating wastewater before it is released into municipal sewer systems.
“This new facility will help to ensure that Resource Recovery is completely compliant with all modern wastewater treatment standards, and will employ approximately 160 Rhode Island workers in the construction sector through early 2015,” said Mike OConnell, RIRRC’s executive director.
It is not clear whether the £27 million quoted includes for operational costs for a period after construction, but at this price the plant must certainly be the most expensive contract ever.
A second US leachate pre-treatment plant which has just commenced construction is also in the news, this time it is located at the Monmouth County Reclamation Center in New Jersey.
The investment must be substantial, and in thic case the contract does include operational of the plant after construction, but no figures have been given in the press releases we have seen.
We include further information on this second leachate pre-treatment plant below:
Applied Water Management (AWM), a wholly-owned subsidiary of Natural Systems Utilities (NSU), has broken ground along with Middlesex Water Company on a new leachate pretreatment facility at the Monmouth County Reclamation Center in Tinton Falls, New Jersey, US.
The companies have partnered to design, construct and operate the facility under an initial 15-year contract with Monmouth County.
Monmouth County Reclamation Center superintendent Richard Throckmorton said that a long-term public-private partnership with the local New Jersey companies enables the county to have in place a system to manage wastewater with long-term reliability and flexibility, designed to accommodate future regulations.
The project includes a new wastewater treatment plant, which employs an advanced membrane bioreactor (MBR), pump station and pipeline that connects to the local sewer utility.
The MBR technology provides a high level of treatment that helps protect the environment by removing over 500,000lbs of nitrogen and over 1,000lbs of heavy metals from the waste stream every year.
NSU-AWM executive vice president Richard Cisterna said that using an advanced MBR reduces the amount of untreated leachate hauled off-site, significantly lowering operating costs and positively impacting the environment.
These two plants, due to the cost involved, must surely raise the profile of leachate treatment in the US, both within the public who will in the end be paying for them, and the water treatment industry which will need to create specialized water treatment process systems for the special nature of leachate, if these plants are to operate reliably and efficiently.