IMMEDIATE NEWS RELEASE
October 17, 2007
Contact: Denise Chew
Phone: (704) 588-7970
Email: DeniseChew@enviroequipment.com
Enviro-Equipment promotes Manager from within and enhances its work force with experience and performance.
For over 14 years the experienced environmental professionals at Enviro-Equipment have provided quality environmental rental equipment and products. With a history of being an industry leader in its profession, it’s not a surprise to see quality employees rising to managerial positions from within the company.
In June of 2005, EEI hired Danielle Mozingo from Phillip Morris to serve as their Administrative Assistant. During the last 2 years, Danielle has proven herself time and again with a performance that affects not only the bottom line of the company but the quality of its customer service. In July of 2007, Danielle was promoted to Office Manager at Enviro-Equipment Inc.
As a newly qualified Public Notary, Danielle brings 9 years of Human Resources experience from Longs Drug Stores and Administrative Assistant experience from Phillip Morris. Danielle will now add Accounting, Payroll, Collections and Client Coordination to her already wide array of skill sets.
Enviro-Equipment, Inc.(EEI), is a North Carolina certified "Woman-Owned Business Enterprise" incorporated in January, 1993. EEI is located at 11180 Downs Road in Charlotte, North Carolina 28134. In 2004, EEI opened a Remediation Systems warehouse at 10120 Industrial Drive in Pineville, NC 28134.
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Denise Chew
President
Enviro-Equipment Inc.
Office: 704-588-7970
www.enviroequipment.com
Friday, October 12, 2007
Friday, October 5, 2007
Accurate information for field soil screening procedures
Are your field soil screening procedures providing you with practical and accurate information?
Environmental consulting activities frequently require that on-the-spot decisions be made in the field concerning the presence or absence of volatile, or even semi-volatile, organic compounds (VOC's) in soil. There is nothing that can replace the value of field experience in "making the right call" when the trucks are lined up, the backhoe operator is waiting, and the client is watching the hole in the ground get bigger and bigger. However, the application of basic knowledge and consistent methodology to your field procedures can assist you in the interpretation of field soil screening results.
First, are you using the right piece of equipment for the job? You have to understand the capabilities and limitations of the Organic Vapor Analyzer (OVA) you are using.
A Photo-Ionization Detector (PID) will be limited in its response by the electron voltage (eV) output of the lamp in the instrument. Most VOC's have a published Ionization Potential (IP). PID's are equipped with a 9.5 eV, 10.6 eV, or 11.7 eV lamp. The 10.6 eV lamp is the most common. In order for a PID to respond to a particular VOC, the IP of the compound of interest must be less than or equal to the eV output of the lamp. There are some compounds that a PID will not detect, most notably methane. In addition, methane can chemically mask the presence of VOC's. PID's are subject to poor performance in the presence of high humidity in moist soil. Perhaps the greatest advantage in using a PID is that it does not require a hazardous gas for operation. This can be a great consideration in logistics or cost when traveling or working in an isolated area.
A Flame-Ionization Detector (FID) will respond to most VOC's by nature of its destructive detector function. An FID will not be adversely affected by the presence of humidity in moist soil. An FID can be used in methane determination or differentiation by using a charcoal filter adapter. FID's are calibrated to methane. A charcoal filter adapter absorbs VOC's that are present in a sample. Therefore, the determination or differentiation of the presence of VOC's can be made in the presence of methane. Perhaps the greatest disadvantage in using an FID is the need for zero-grade or ultra-high purity (UHP) hydrogen for the detector's flame fuel source. Once again, this can be a great consideration in logistics or cost when traveling or working in an isolated area.
Whichever OVA you are using, current manufacture instruments provide sub-parts per million (ppm) digital performance and, usually, dynamic ranges of 10,000 ppm, or higher. Due to the differing responses instrument to instrument, do not change from a PID on one phase of work to an FID on another phase of work. From a practical perspective, both instruments are field-screening tools, not laboratory analysis equipment. If a soil sample exhibits a gross VOC odor that you cannot even stand to get near, you may actually harm the instrument you are using by analyzing such a sample. You may want to consider a company standard field note procedure for such samples rather than risking the contamination of the OVA's detector system.
Second, you have to understand the nature of volatile organic compounds and semi-volatile organic compounds as they relate to actual laboratory-testable product in the soil sample versus the amount of vapor in a soil sample headspace. The principle is simple. The headspace vapor-in-air concentration of a highly volatile compound may be higher than the actual laboratory-testable amount of the compound in the soil sample as you go from contaminated to clean soil. The opposite is true for semi-volatile organic compounds. The headspace vapor-in-air concentration of a semi-volatile compound may be lower than the actual laboratory-testable amount of the compound in the soil sample as you go from contaminated to clean soil.
Third, are you simply waving the instrument's sample probe over an open split-spoon, handful of soil, or open excavator bucket or are you head-spacing your soil samples?
There are too many uncontrolled factors present in simply waving the instrument's sample probe over an open split-spoon, handful of soil, or open excavator bucket. In most instances, your OVA will only respond to gross levels of contaminants when using this method. Additionally, outdoor ambient airflow will affect the sample that gets drawn into the OVA. In windy conditions, you might actually be detecting VOC's from a background source, such as heavy construction equipment or gas pumps. This method provides no controlled methodology to make a determination of what's happening sample to sample. It also allows no time for semi-volatile VOC's to release vapors that can be detected by an OVA.
Head-spacing soil samples provides for the best possible application of consistent and controlled methodology to your field soil screening procedures. The key word here is consistent. The container you use, amount of soil you collect, or amount of time the containerized soil sample sits are not so important as being consistent with each one. Glass jars with foil and zip-closure bags are commonly used for head-spacing procedures. Use the same type of container for all phases of work. Glass jars heat up faster and stay cold longer than a zip-closure bags. If using zip-closure bags, test a bag first to make sure that it does not in itself release VOC's that will be picked up by your OVA. Collect the same amount of soil with each sample. Most importantly, allow each containerized soil sample to sit for the same amount of time. A very common error is to collect samples over the course of the day and then check them all at the end of the day. One sample may have been sitting for five minutes while the first one has been sitting for five hours! It is usually sufficient to allow a sample to sit for a matter of minutes to provide for a practical indication of the presence or absence of VOC's.
The best possible scenario for controlled soil sample screening, using the headspace method, is to split samples between two containers. This applies to soil samples that are being screened for potential submission to a laboratory and to soil samples that are being screened for differentiation of VOC's and methane. In the first instance of screening, the sample to be screened should be containerized for head spacing. The potential laboratory sample can be tightly wrapped in a zip-closure bag, wrapped in foil, and placed in a cooler for later use, if necessary. In the second instance of methane differentiation, the sample should be split between two containers, and then screened individually using the FID on one and the charcoal filter adapter on the other. A single sample headspace will be depleted by the first analysis and leave an inadequate sample for the second analysis.
In closing, apply these basic principles and procedures to your field soil screening activities. You will find that your field data will provide you and your project professionals with more accurate data. Best of all, though, you'll find that you will more quickly gain the experience necessary to "make the right call" when it counts most, in the field.
Chris Nagy
Corporate Consultant
EEI Reaches out to clients with information
Dear Colleagues,
Are your field soil screening procedures providing you with practical and accurate information? In this article, written by our corporate consultant, Chris Nagy, you will find those never revealed tips in order to obtain the most accurate information possible in the process of soil screening. You will also find how Enviro-Equipment, Inc. can help if you are involved with the re-building process concerning Hurricanes Rita and Katrina's affected zones.
We also just upgraded our website in order to meet with your demands for information concerning rental and/or remediation equipment. The new EEI website is full of information to help you select the right equipment, solve those tricky problems, and converse with other environmental professionals in a friendly forum.
It is difficult to cover every aspect of a broad field such as environmental in just one article, so if you don't find information for your specific field here, I encourage you to keep on checking future entries. I will do my best to cover as much information from as many areas as possible. You can also email me your questions at brianchew@enviroequipment.com. I will be more than happy to help you!
Brian Chew Sr. P.G.
Enviro-Equipment Inc.
Thursday, October 4, 2007
Sampling 101 – Pump or Bailer? - Part 3 of 3
CONCLUSIONS
Each ground-water sampling situation must be carefully considered before making a decision to use a bailer or pump, and the following chart may be of some use in making that decision. Remember that the skill and experience of the operator is of great importance in obtaining a representative sample of the ground water, but choice of the sampling method is also important, and can make a big difference in the eventual cost of your sampling project. Consult your local environmental equipment agent for specifications, costs, or other information regarding bailers and pumps, and be sure to consult their resident experts for their advice.
The writer wishes to thank Brian Chew of Enviro-Equipment, for his technical advice with this article.
Each ground-water sampling situation must be carefully considered before making a decision to use a bailer or pump, and the following chart may be of some use in making that decision. Remember that the skill and experience of the operator is of great importance in obtaining a representative sample of the ground water, but choice of the sampling method is also important, and can make a big difference in the eventual cost of your sampling project. Consult your local environmental equipment agent for specifications, costs, or other information regarding bailers and pumps, and be sure to consult their resident experts for their advice.
The writer wishes to thank Brian Chew of Enviro-Equipment, for his technical advice with this article.
Sampling 101 – Pump or Bailer? - Part 2 of 3
SAMPLING PUMPS Pumps for field sampling are of several types; all are geared to purging and sampling ground water with a minimum of water turbulence and sample quality, and a maximum of operational ease. Advantages for the low flow portable pumps over bailers are that they reduce the amount of purge water removed from a well, which means less water to dispose of afterwards; low flow may also reduce the agitation of the formation water, therefore decreasing fluid turbulence and the potential for turbidity and aeration, which may increase inaccuracy and inconsistency of sample results. The optimum pumping rate should be equal to or less than the natural recovery rate of the well – this can be determined with continuous water-level measurements using an electronic water-level indicator. Disadvantages of low-flow pumps over bailers are the initial cost, the difficulty of cleaning (if the pump and tubing are not dedicated); and the possibility of sample water being subject to increases or decreases in air pressure during retrieval, which has a tendency to skew analytical results of volatiles. 
Battery driven portable pumps are small, cylindrical water pumps of varying diameters and capacities that are lowered into a well for purging and sampling. They are attached to wires (to be connected to a battery power source) and tubing (to allow the water to reach the surface for purging and sampling). They come in a variety of designs, sizes, capacities, and specifications. Manufacturers include Proactive, Whale and others; specification sheets are available from the manufacturer or environmental equipment suppliers. Advantages of this type of portable pump are the lower initial cost (typically about $100 for a small pump), ease of operation, and capability of very low flow to avoid problems with turbidity. However, they are limited in the effective sampling depth, and have much lower flow rates than standard electric pumps. With power boosters (to increase voltage from 12 to 24 volts), the sampling depth could be increased to around 200 feet. These pumps typically have an effective life of 400 to 600 hours of operation, so are not cost-effective with long term operation. Bladder pumps. The bladder in this type of pump is a balloon-like device inside the cylindrical pump housing, attached to an air line which extends from the bladder pump to the surface. The pump housing has two check valves and a water discharge tube that extends to the surface. When you lower a bladder pump into the well, water pressure causes the bladder to fill with water through one of the check valves. Compressed air or nitrogen is pumped through the air line into the annulus between the bladder and the pump housing, forcing the well water to exit the bladder through the other check valve and into the water discharge tubing. The process is repeated until the desired water volume is discharged. Advantages of this system are that extremely low flow rates may be obtained, to prevent turbidity or aeration, and to allow for very slow recharge rates in adverse hydrogeologic conditions. In addition, there is no limit on the depth, as the water is pushed to the surface. Disadvantages are the cost, which vary from $1000 on up, and the slow operation, which can be inefficient in larger wells where greater volume is desired for purging. Electric pumps. A third type of pump is the electric pump, made by several manufacturers, including Grundfos. This pump can deliver fairly low flow volumes (as low as 200 milliliters per minute), but has the option of higher flow rates if needed for purging. It also needs a generator or power source. Electric pumps are the most expensive, initially - a good electric pump setup, including generator, can cost upwards of $3000. However, these pumps have an effective working depth of 300 feet, and are sturdily built enough to last for many years. By Orrin Hall
Battery driven portable pumps are small, cylindrical water pumps of varying diameters and capacities that are lowered into a well for purging and sampling. They are attached to wires (to be connected to a battery power source) and tubing (to allow the water to reach the surface for purging and sampling). They come in a variety of designs, sizes, capacities, and specifications. Manufacturers include Proactive, Whale and others; specification sheets are available from the manufacturer or environmental equipment suppliers. Advantages of this type of portable pump are the lower initial cost (typically about $100 for a small pump), ease of operation, and capability of very low flow to avoid problems with turbidity. However, they are limited in the effective sampling depth, and have much lower flow rates than standard electric pumps. With power boosters (to increase voltage from 12 to 24 volts), the sampling depth could be increased to around 200 feet. These pumps typically have an effective life of 400 to 600 hours of operation, so are not cost-effective with long term operation. Bladder pumps. The bladder in this type of pump is a balloon-like device inside the cylindrical pump housing, attached to an air line which extends from the bladder pump to the surface. The pump housing has two check valves and a water discharge tube that extends to the surface. When you lower a bladder pump into the well, water pressure causes the bladder to fill with water through one of the check valves. Compressed air or nitrogen is pumped through the air line into the annulus between the bladder and the pump housing, forcing the well water to exit the bladder through the other check valve and into the water discharge tubing. The process is repeated until the desired water volume is discharged. Advantages of this system are that extremely low flow rates may be obtained, to prevent turbidity or aeration, and to allow for very slow recharge rates in adverse hydrogeologic conditions. In addition, there is no limit on the depth, as the water is pushed to the surface. Disadvantages are the cost, which vary from $1000 on up, and the slow operation, which can be inefficient in larger wells where greater volume is desired for purging. Electric pumps. A third type of pump is the electric pump, made by several manufacturers, including Grundfos. This pump can deliver fairly low flow volumes (as low as 200 milliliters per minute), but has the option of higher flow rates if needed for purging. It also needs a generator or power source. Electric pumps are the most expensive, initially - a good electric pump setup, including generator, can cost upwards of $3000. However, these pumps have an effective working depth of 300 feet, and are sturdily built enough to last for many years. By Orrin Hall
Wednesday, October 3, 2007
Sampling 101 – Pump or Bailer? - Part 1 of 3
As portable pumps for sampling ground water have become more and more common, beginners in the field of environmental sampling have asked for some guidelines for choosing between the portable pumps and the older methodology of bailers. This article is an attempt to describe types of bailers and portable, low-flow submersible pumps, the differences between them with regard to purging and sampling, and to give a cursory review of the advantages and disadvantages of each with respect to sample quality. Other sampling methods, not discussed in this article, are the hydropunch, suction and inertia pumps, and air-lift pumps.
BAILERS Bailers are hollow cylindrical tubes with a device on the top to lower or raise the bailer by a cord into a well, and a device, called a check valve, on the bottom to allow water to enter and to stay in the bailer while raising it from the well. They vary in length and diameter according to the well sampled and the volume desired, and in design according to the contaminant sampled. Water collected from a well may be poured into a separate sample container, such as a glass volatile organic analysis (VOA) container by releasing a valve on the bottom of the bailer (the check valve) into the sample container. Bailers come in a variety of either reusable or disposable design, and of various materials. Some of the advantages of bailers are low cost, portability, and ease of use. Bailers also have their disadvantages; they can be very time-consuming, if also used for purging the well; they are ineffective in large diameter or very deep wells; the depth of the sample point within the aquifer may be difficult to determine; freezing temperatures or very turbid well water may affect check valve operation; poor design may increase aeration or turbidity in the water sample, thus affecting sample quality; and the operator may be adversely exposed to contaminants. All bailers require technique and skill to operate effectively and efficiently – there is no substitute for skill in obtaining a good sample. Recent developments in bailer design include a larger ball in the check valve, the larger opening allowing the bailer to sink more quickly without causing more turbulence. Bailers may also use clear polyvinyl chloride (PVC), which is denser than polypropylene (PP); the additional density precludes the necessity of weighting the bailer.
Disposable bailers are designed to be used only once and disposed of after sampling. Modern disposable bailer designs, such as Ecobailer, Aqua Bailer or Clearwater Engineering, have incorporated dependable check valves and non-binding valve end designs. Disposal Teflon and PVC bailers are heavy enough to facilitate non-turbulent entry into the water column; however, PP is lighter, with a specific gravity less than water (it floats), and typically requires weighting to facilitate sinking. Advantages of disposable bailers are that they are reasonably inexpensive and available in bulk, and they are decontaminated and sealed in a clean room environment, virtually guaranteeing that the sample is free of contamination. Because they are only used once and disposed of, the sampler does not need to bring decontamination solutions or equipment into the field, saving time and additional expense during field operations.
Reusable bailers are meant to be, as the name implies, reused many times. Reusable bailers are typically made of stainless steel or Teflon, and are designed to withstand cracking and weakening where the bailer cord is attached. They and are made of strong, resistant material to help protect the check valve from scratches, which could cause the sample to be lost or compromised. They are also made sturdily, in order to be taken apart and cleaned. Reusable bailers are typically made of heavier materials, allowing them to sink more quickly into the well for efficient purging and sampling. Various reusable bailer manufacturers, such as Norwell, have online specification sheets available for comparison, which may be obtained through various equipment dealers or retailers, such as www.enviroequipment.com. Reusable bailers are cleaned and sealed before using to guarantee the sample is free from contamination; they must be cleaned and decontaminated after sampling and before reuse.
By Orrin Hall
BAILERS Bailers are hollow cylindrical tubes with a device on the top to lower or raise the bailer by a cord into a well, and a device, called a check valve, on the bottom to allow water to enter and to stay in the bailer while raising it from the well. They vary in length and diameter according to the well sampled and the volume desired, and in design according to the contaminant sampled. Water collected from a well may be poured into a separate sample container, such as a glass volatile organic analysis (VOA) container by releasing a valve on the bottom of the bailer (the check valve) into the sample container. Bailers come in a variety of either reusable or disposable design, and of various materials. Some of the advantages of bailers are low cost, portability, and ease of use. Bailers also have their disadvantages; they can be very time-consuming, if also used for purging the well; they are ineffective in large diameter or very deep wells; the depth of the sample point within the aquifer may be difficult to determine; freezing temperatures or very turbid well water may affect check valve operation; poor design may increase aeration or turbidity in the water sample, thus affecting sample quality; and the operator may be adversely exposed to contaminants. All bailers require technique and skill to operate effectively and efficiently – there is no substitute for skill in obtaining a good sample. Recent developments in bailer design include a larger ball in the check valve, the larger opening allowing the bailer to sink more quickly without causing more turbulence. Bailers may also use clear polyvinyl chloride (PVC), which is denser than polypropylene (PP); the additional density precludes the necessity of weighting the bailer.
Disposable bailers are designed to be used only once and disposed of after sampling. Modern disposable bailer designs, such as Ecobailer, Aqua Bailer or Clearwater Engineering, have incorporated dependable check valves and non-binding valve end designs. Disposal Teflon and PVC bailers are heavy enough to facilitate non-turbulent entry into the water column; however, PP is lighter, with a specific gravity less than water (it floats), and typically requires weighting to facilitate sinking. Advantages of disposable bailers are that they are reasonably inexpensive and available in bulk, and they are decontaminated and sealed in a clean room environment, virtually guaranteeing that the sample is free of contamination. Because they are only used once and disposed of, the sampler does not need to bring decontamination solutions or equipment into the field, saving time and additional expense during field operations.
Reusable bailers are meant to be, as the name implies, reused many times. Reusable bailers are typically made of stainless steel or Teflon, and are designed to withstand cracking and weakening where the bailer cord is attached. They and are made of strong, resistant material to help protect the check valve from scratches, which could cause the sample to be lost or compromised. They are also made sturdily, in order to be taken apart and cleaned. Reusable bailers are typically made of heavier materials, allowing them to sink more quickly into the well for efficient purging and sampling. Various reusable bailer manufacturers, such as Norwell, have online specification sheets available for comparison, which may be obtained through various equipment dealers or retailers, such as www.enviroequipment.com. Reusable bailers are cleaned and sealed before using to guarantee the sample is free from contamination; they must be cleaned and decontaminated after sampling and before reuse.
By Orrin Hall
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