PAHs and BTEX are present in soil and groundwater surrounding many former gas plants, which is why most of these sites are designated for remediation.  The remedial actions taken depend on the type and extent of contamination, but often involve excavation and soil remediation.  Excavated soil and any other exposed soils are contained within a temporary structure in order to control the release of contaminated vapors during remediation. These vapors are then captured for treatment before releasing to ambient air.

Due to the often large amounts of excavated soil, the corresponding containment structure and treatment system must also be quite large.  The soil vapors are passed through a large adsorption vessel, where the molecules of contaminants attach themselves to the solid surface of the activated carbon in the vessel.  The vapors are withdrawn from the containment structure, passed though the treatment media, and discharged to atmosphere using large centrifugal blowers.

To learn more about the history of MGPs, the current state of these facilities, and the treatment options, please read this excellent document from the New York State Department of Environmental Conservation.  For more information, there is also a discussion group on LinkedIn focused on MGP Remediation.

Remediation of excavated soil at MGP sites is typically a short-term endeavor,  on the scale of months rather than years, making it hard to justify the purchase of capital equipment.  Consequently, renting treatment equipment is a popular choice for this type of project.  MLE Equipment has an entire series of treatment systems designed specifically for MGP sites, available for rent across North America.

Our MGP-Series of treatment systems are housed in standard shipping containers, with the majority of the system consisting of the actual adsorption vessel.  The systems have large vapor inlets, particulate filters to protect the equipment, high-capacity centrifugal blowers, and up to 32,000 lbs. of vapor-phase activated carbon.  This all adds up to a maximum performance of 27,000 CFM, large enough for almost any application.

MGP-Series remediation systems are available for any rental term, and come fully-assembled and factory-tested.  Our systems are suitable for Class 1 Division 2 locations, and can also come equipped with wireless telemetry for remote system control. To complement these systems, we also offer rental generators for site power, and dewatering equipment.

It is estimated that there are over 1,200 decommissioned MGPs across the US, with more sites in Canada.  Remediation of these sites will obviously be a concern for years to come, as the plants were built in populated areas, mainly along waterways.  For the treatment of excavated soil, rental equipment is often the best solution, and MLE Equipment has the rental equipment to satisfy most requirements.

Part of our effort to achieve positive project outcomes, and to improve the content of mleequipment.com, is to produce a series of customer guidelines.  While technical whitepapers fill the role of providing in-depth technical information on technologies and equipment, these guidelines are designed to assist our customers with the design and procurement of systems.

The first phase to be focused on in the Design and Procurement Guidelines is the selection, design, and pricing of equipment.  Equipment vendors are capable of providing much more than just full proposals for systems; they can also assist with equipment selection and design, budget pricing, system layouts, and much more.  The guideline Phase 1: Equipment Selection, Design, and Pricing discusses these offerings, and provides a case study as an illustration of the typical process.

This first guideline will be followed up with at least two more, focusing on the engineering and manufacture of remediation equipment, and the services available to customers once the equipment is on site.

Another goal of these guidelines is to engage our customers in a discussion about the process of designing and procuring remediation equipment.  Input from our customers is important, as it will help improve our processes and outcomes.  Please read the guidelines, and comment on this blog to begin the discussion.

]]> http://www.mleequipment.com/environmental-technology-blog/2011/design-and-procurement-guidelines/feed/ 0 http://www.mleequipment.com/environmental-technology-blog/2011/building-remediation-systems-for-noise-sensitive-locations-2/ http://www.mleequipment.com/environmental-technology-blog/2011/building-remediation-systems-for-noise-sensitive-locations-2/#comments Fri, 21 Jan 2011 16:07:06 +0000 deanna http://www.mleequipment.com/?p=4654 MLE Equipment’s customers are encountering more-stringent municipal noise by-laws for remediation equipment.  These noise by-laws vary between municipalities, with requirements depending on several factors including:

• the type of site  – residential, commercial, or industrial
• the types of receptors involved – residential, commercial, or industrial
• the type of equipment being operated
• the time of day, with different standards for day- and night-time operation

Illustrating this variability are examples of maximum-allowable noise levels from a few different geographical locations:

• New York, NY – 50 to 70 dBA depending on location and time of day
• Ottawa, ON – 50 dBA at point of reception
• San Francisco, CA – 5 to 10 dBA above ambient noise level at the property line

Difficulty arises because these maximum levels are extremely low, especially when compared to typical noise sources.  Referring to the table below, it is obvious that requirements of 50 dBA are significantly lower than common urban sources such as construction sites (90 dBA) and street traffic (80 dBa).

The sound generated by a remediation system varies depending upon the equipment makeup in the system, but will typically fall in the range of 70 to 100 dBA; the loudest piece of equipment will always drive the overall noise level of the system.  The other important factor is the frequency of the noise signature.  Traditionally, remediation systems have been designed for noise-sensitive areas by placing the equipment inside an enclosure, with sound insulation installed on the interior and in hoods over ventilation openings.

However, this approach is no longer sufficient with maximum-allowable noise levels as low as 50 dBA (and even lower in some cases).  In these noise-sensitive locations, the overall effectiveness of the remediation system must include its ability to meet the site’s noise requirements.  Complaints from a local receptor (neighboring resident, store owner, school, etc.) could result in system operation being limited to certain time periods, or being stopped altogether.  Any disruptions to the operation of remediation equipment are obviously not desirable, as the effectiveness of the project is affected and equipment costs become an issue.  Recognizing the importance of addressing noise concerns, we are improving our understanding of noise as it relates to remediation equipment.

MLE Equipment is taking a two-pronged approach when designing remediation systems for noise-sensitive areas:

1. Reducing the source – selecting equipment with lower noise ratings
2. Mitigating noise coming from the equipment – building enclosures, mufflers, isolators, etc.

We have worked extensively with Acoustics Engineers to assess the noise levels and frequencies of the major components in remediation systems.  Using this information we have established the tools, knowledge, and resources required to determine appropriate design approaches to best mitigate noise, including:

• consideration of building materials and construction techniques
• appropriate isolation of equipment to reduce vibration
• methods for handling required building openings such as ventilation and doors

Without revealing too much information about our design and construction techniques, which we continue to improve, we can now build remediation systems that satisfy noise requirements as low as 50 dBA.  Please view the following video for an illustration of what we’ve accomplished – you have to hear it to believe it!

MLE Equipment has made meeting its customers’ noise requirements a priority and we’ve armed ourselves with the knowledge and resources to be able to properly “tune” an acoustic solution for noise-sensitive locations.

References:

1. Noise Control for Engineers, Lord, Gatley, Evenson; Krieger 1987

In North America, this push to go green is a major driving force in the growth of Membrane Biological Reactor (MBR) technology in wastewater applications. MBR technology is quickly replacing conventional Sequencing Batch Reactor (SBR) and Rotating Biological Contactor (RBC) technology in small, medium, and large applications.

But the reason for the rapid acceptance and implementation of Membrane Biological Reactor technology goes beyond “going green”. MBR is one of those exceptional technologies that also make sense from a purely financial and operational perspective. A true win-win.

In this post I like to share some insights into these performance and financial advantages of MBR, and what, if any, technical limitations exist for this relatively new technology to North America.

What is Membrane Biological Reactor technology?

The MBR process was introduced to the market in the late 1960s, when ultrafiltration (UF) and microfiltration (MF) membranes became commercially available in large scale. Wikipedia provides a good description of MBR, so I won’t go into a detailed explanation here.

Essentially, membrane bioreactor technology is a simple, yet effective combination of an activated sludge biological treatment process with membrane filtration. Membranes with pore size of 0.04 – 0.1 microns act as a physical barrier allowing the passage of clean water, while trapping suspended solids, bacteria, pathogens and certain viruses. The membrane filter eliminates the need for a secondary clarifier and for tertiary filtration. The MBR process supports a high biomass concentration, as a result reducing the required size of biological tanks; this in turn saves space and reduces overall construction cost. Overall, the MBR can reduce the footprint of a wastewater treatment plant by as much as 75%.

This space saving feature is one of the reasons that Membrane Biological Reactor technology became rapidly deployed in Europe, primarily in large municipal wastewater applications, where it was put through its paces to become a mainstream, reliable technology.

Tighter Environmental Regulations in North America are driving MBR demand

Although Europe had the early lead, North America is now quickly embracing the environmental call-to-action on wastewater.  Governments at all levels – federal, provincial or state, and municipal – are in the process of implementing stricter effluent regulations, and all see MBR as a win-win solution.

Here in Canada, the Federal Environment Minister recently unveiled a move to stringent wastewater regulations while touring our MBR production facility. The Ontario Provincial Government has initiated a “water is gold” program to treat and reuse this precious resource that we all need. This in a country that holds an estimated 20% of the world’s fresh water. You can imagine what the environmental pressure will be in countries or regions with less bountiful fresh water resources.

Membrane Biological Reactor technology is capable of turning wastewater into “potable-like” water, with BOD of less than 5 ppm and undetectable E. coli. This means that effluent can be released directly to any environment, no matter how ecologically sensitive, or safely reused in applications like irrigation in agriculture or golf clubs. An MBR wastewater system can actually become a positive differentiator for communities with strong pro-environment  stakeholders.

Performance/ Financial benefits are driving MBR demand

Space savings is a big reason for increasing MBR demand, even in North America. In many urban areas, wastewater plants are surrounded by development, and area expansion is not an option.

There is also a huge push to decentralization, and smaller, decentralized systems offer substantial cost benefits over expanding existing sewage treatment lines to feed larger, centralized plants. Smaller, decentralized systems minimize the need to dig up infrastructure, disrupt services, and other costs related to building huge sewage feeder systems. In one recent implementation, a $400,000 decentralized MBR system eliminated the cost of $3,000,000 of additional sewage treatment lines.

And although the direct capital cost of MBR systems can be 10 to 20% higher than conventional technologies, Membrane Biological Reactor systems can also be substantially less expensive to operate and maintain – especially when integrated with new telemetry monitoring and remote control.

Is there still a place for conventional SBR and RBC technologies?

Both SBR and RBC technologies have been used for decades across North America, and still represent the majority of installations. There is a lot of design, installation, and operation experience that is still focused on these traditional technologies, and although the momentum is shifting because of stricter effluent regulations, it will take time to complete the shift to MBR.

And Membrane Biological Reactor technology is more sophisticated and does require considerable expertise to ensure that it performs as specified, and delivers all of its environmental and operational benefits. In the end, sewage makeup can be highly variable, and application-engineering needs to customize each MBR solution for the specific “biology” of the wastewater application, including BOD, flow rates, phosphates, nitrogen, oils and greases, and other contaminants.

Next Up: Some interesting MBR case studies

Because of all these inherent strengths in the MBR process, Membrane Bi0logical Reactor treatment is being adopted in small/medium application such as condominiums, hotels, resorts, golf clubs, mining camps, small villages and subdivisions. In some instances these implementations of MBR are right next to environmentally sensitive areas such as conservation areas, rivers, and lakes.

Which will lead to the next post. A case study of a hotel and condominium complex that was dumping raw sewage into a major river, and how we turned that wastewater into a water stream cleaner than the river it discharges into.

———————————————–

John Dragasevich is Founder and President of Filter Innovations Inc., a member of the Calco Environmental Group. Filter Innovations is a leading supplier of innovative treatment solutions for process water, wastewater, ground water, and air, including Membrane Biological Reactor Systems, Air Scrubber Systems, Chemical Waste Treatment Systems, Dissolved Air Flotation Systems, Engineered Filter Systems, Odour Control Systems, and Ultra Filtration Systems.

An overview of MLEE’s Telemetry System: Site-Link 2010

Telemetry technology enables the remote monitoring, measurement, reporting and control of a process. It gives users the ability to remotely login to a system, and then change its parameters, review data logged over a period of time, or study metrics used to determine the efficiency and productivity of a system.

We call our telemetry technology “Site-Link”, and we begin this post by listing its many advantages:

1. Telemetry allows one to measure and monitor the system’s performance remotely, and to make suitable control adjustments without having to travel to the site.
2. Sites can be operated “un-manned” while still retaining the full security of 24-hour surveillance and control.
3. Larger site owners have the ability to conveniently monitor, control and troubleshoot multiple sites from one location.
4. Differential pressure transmitters enable telemetry to indicate to an operator, for example, when regular maintenance like carbon or bag filter replacements are needed.
5. Site-link makes it possible to trouble-shoot a site remotely thus allowing the site manager to dispatch a tech to the site with the right tools and parts to effect a complete repair in the minimum time.
6. One seasoned, experienced operator can look after many sites, reducing maintenance and repair times, effectively boosting uptime and overall performance.

In other words, telemetry saves time, reduces people costs and improves system performance.

MLEE led the development of integrating telemetry into remediation equipment with the introduction of Site-Link over 10 years ago. At that time, the system was based on an auto-dialer. Auto-dialers call a pre-programmed phone number or pager to deliver a message when they receive an alarm signal. But dial-up was costly to install on sites that do not already have an existing phone line, and we thus adapted Site-Link to use cellular technology. Today’s digital transmission of data over cellular networks all but eliminates the transmission errors of previous analog phone lines.

The latest release of our telemetry technology, Site-Link 2010, is a web-based telemetry package giving site operators all the features offered in previous versions, with the following improvements.

• Platform Independence: Site-Link 2010 eliminates any form of software installation. By allowing any web browser to control and operate the system, Site-Link 2010 solves the issue of supporting a number of computing technologies (PC, Mac, Linux, Window XP, Vista, etc.).
• Simplified end-user operation via a new, easy-to-use interface, giving users an intuitive way to operate their systems.
• Increased data logging capabilities: Site-Link 2010 increased the amount of data a system logs to virtually unlimited. Unlike traditional telemetry systems, which store the data locally in the PLC, Site Link 2010 stores the data in a remote SQL database. This overcomes the memory limitations of the PLC, removing the need for the operator to upload the data files on a regular basis. It also provides an easy, reliable form of data backup, with records dating back to the commissioning of the system. This data can be accessed at anytime by the operator and can also be uploaded into a CSV file for further analysis.
• Site-Link 2010 supports multiple user roles with varying levels of access; such as Administrator (add/delete/edit users), who then creates Users with specific access to the site (read/write or read only access).
• Improved security: Site Link 2010 has a high level of security control to ensure that only authorized users can access the remote system.

Please contact your local MLE Equipment representative for a complete demonstration.

All these features were designed to make your online experience more enjoyable and productive. And, hopefully, to surprise you by revealing just how powerful a resource for environmental remediation equipment the site now is.

We’re also very proud of the new Resource Library’s four sections:

Equipment Information such as operation and maintenance manuals to guide our customers on the proper maintenance techniques and schedules for their equipment, and to troubleshoot many technical issues. 

The Learning Center contains information about remediation and treatment technologies, terms used in the industry, and emerging trends.  Information is presented in different formats, from extensive white papers, to shorter technical papers, to brief videos.

Equipment Videos: From now through the Spring of 2011, we will be producing instructional videos on over 50 of our most popular products and components.  Additional videos will demonstrate various applications of remediation and treatment equipment.  Please bookmark this page and check back often, as our video library is growing.

Environmental Remediation Industry Links: A collection of links to our suppliers, associated companies and sales agents. We’re proud of the caliber of our equipment, and our suppliers are an important part of that quality circle. More detailed information on particular components and services is available on our suppliers and associates websites.

We hope to establish our site as a hub for the environmental remediation equipment industry. In time, you will find a discussion forum hosted by industry experts, an extensive set of thought-leadership whitepapers and videos, and a vast selection of product and system specifications.

And let’s not forget about this blog. Here we will regularly post articles and insights on the latest news, trends and ideas in environmental remediation technology and the environmental remediation industry.  Some of our customers are the leading consultants in their fields. We hope from time to time to post an article of theirs on our blog, giving you insights into how they use our equipment to design highly efficient solutions that deliver the lowest total cost of ownership to their owners.

In short, our new site is designed to become The Site for your information needs regarding environmental remediation equipment. And if you would like us to add a section on something you feel is missing, please email us with your suggestions.

I look forward to working with you in 2011!

Bruce Lounsbury – President, MLE Equipment