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February 14, 2020by Olga Loreto Olga Loreto No Comments

Groundwater Remediation Techniques

Groundwater remediation techniques span biological, chemical, and physical treatment technologies. Most groundwater treatment techniques utilize a combination of technologies. Some of the biological treatment techniques include bioaugmentation, bioventing, biosparging, bioslurping, and phytoremediation. Some chemical treatment techniques include ozone and oxygen gas injection, chemical precipitation, membrane separation, ion exchange, carbon absorption, aqueous chemical oxidation, and surfactant enhanced recovery. Some chemical techniques may be implemented using nanomaterials. Physical treatment techniques include, but are not limited to, pump and treat, air sparging, and dual phase extraction.

Biological treatment technologies

Bioaugmentation

If a treatability study shows no degradation (or an extended lab period before significant degradation is achieved) in contamination contained in the groundwater, then inoculation with strains known to be capable of degrading the contaminants may be helpful. This process increases the reactive enzyme concentration within the bioremediation system and subsequently may increase contaminant degradation rates over the nonaugmented rates, at least initially after inoculation.

Bioventing

Bioventing is an on-site remediation technology that uses microorganisms to biodegrade organic constituents in the groundwater system. Bioventing enhances the activity of indigenous bacteria and archaea and stimulates the natural in situ biodegradation of hydrocarbons by inducing air or oxygen flow into the unsaturated zone and, if necessary, by adding nutrients. During bioventing, oxygen may be supplied through direct air injection into residual contamination in soil. Bioventing primarily assists in the degradation of adsorbed fuel residuals but also assists in the degradation of volatile organic compounds (VOCs) as vapors move slowly through biologically active soil.

Biosparging

Biosparging is an in situ remediation technology that uses indigenous microorganisms to biodegrade organic constituents in the saturated zone. In biosparging, air (or oxygen) and nutrients (if needed) are injected into the saturated zone to increase the biological activity of the indigenous microorganisms. Biosparging can be used to reduce concentrations of petroleum constituents that are dissolved in groundwater, adsorbed to soil below the water table, and within the capillary fringe.

Bioslurping

Bioslurping combines elements of bioventing and vacuum-enhanced pumping of free-product that is lighter than water (light non-aqueous phase liquid or LNAPL) to recover free-product from the groundwater and soil and to bioremediate soils. The bioslurper system uses a “slurp” tube that extends into the free-product layer. Much like a straw in a glass draws liquid, the pump draws liquid (including free-product) and soil gas up the tube in the same process stream. Pumping lifts LNAPLs, such as oil, off the top of the water table and from the capillary fringe (i.e., an area just above the saturated zone, where water is held in place by capillary forces). The LNAPL is brought to the surface, where it is separated from water and air. The biological processes in the term “bioslurping” refer to aerobic biological degradation of the hydrocarbons when air is introduced into the unsaturated zone contaminated soil.

Phytoremediation

In the phytoremediation process, certain plants and trees are planted, whose roots absorb contaminants from groundwater over time. This process can be carried out in areas where the roots can tap the groundwater. A few examples of plants that are used in this process are Chinese Ladder fern Pteris vittata, also known as the brake fern, which is a highly efficient accumulator of arsenic. Genetically altered cottonwood trees are good absorbers of mercury and transgenic Indian mustard plants soak up selenium well.

EE&G Companies, Pollution or Contaminants from Groundwater

February 14, 2020by Olga Loreto Olga Loreto No Comments

Removing Pollution or Contaminants from Groundwater

Groundwater remediation is the process that is used to treat polluted groundwater by removing the pollutants or converting them into harmless products. Groundwater is water present below the ground surface that saturates the pore space in the subsurface. Globally, between 25 percent and 40 percent of the world’s drinking water is drawn from boreholes and dug wells. Groundwater is also used by farmers to irrigate crops and by industries to produce everyday goods. Most groundwater is clean, but groundwater can become polluted, or contaminated as a result of human activities or as a result of natural conditions.

The many and diverse activities of humans produce innumerable waste materials and by-products. Historically, the disposal of such waste has not been subject to many regulatory controls. Consequently, waste materials have often been disposed of or stored on land surfaces where they percolate into the underlying groundwater. As a result, the contaminated groundwater is unsuitable for use.

Current practices can still impact groundwater, such as the over-application of fertilizer or pesticides, spills from industrial operations, infiltration from urban runoff, and leaking from landfills. Using contaminated groundwater causes hazards to public health through poisoning or the spread of disease, and the practice of groundwater remediation has been developed to address these issues. Contaminants found in groundwater cover a broad range of physical, inorganic chemical, organic chemical, bacteriological, and radioactive parameters. Pollutants and contaminants can be removed from groundwater by applying various techniques, thereby bringing the water to a standard that is commensurate with various intended uses.

Removing pollution or contaminants from groundwater, surface water, or contaminated soil is what environmental remediation is all about. But to get the job done successfully, you’ll need to first understand the different cleanup methods and how they work. Here is a list of six proven methods:

1) Ground Water Pumping and Treatment: This method involves the extracting groundwater with a vacuum pump and then separating contaminants with techniques like carbon adsorption, biological treatment, and air stripping

2) Waste Water Treatment: This method removes contaminants from wastewater with techniques such as physical separation, chemical treatment, and biological treatment.

3) Bio-remediation: This method is a natural bio-degradation of contaminants by micro-organisms, which can be enhanced through the addition of nutrients or cultivation.

4) Incineration: This method uses extremely high temperatures to destroy organic compounds contained within the hazardous waste.

5) Thermal Desorption: This method utilizes high temperatures to heat contaminated soil, vaporizing volatile and semi-volatile organics (like mercury hydrocarbon), which are then either collected or treated with an afterburner.

6) Removal and Disposal: This method involves the physical removal of contaminated equipment, soil, water, sludge and/or tanks and transporting it to an approved hazardous waste disposal facility. If it turns out you need to go this route, Hazardous Waste Experts can help you with this. We’re experts at environmental remediation and hazardous and non-hazardous regulated waste disposal.

February 14, 2020by Olga Loreto Olga Loreto No Comments

Best Practices in Contracting for Construction Services

Reducing risk starts before the ground is broken on a construction project. Construction contracts are unique in that they anticipate change will occur during the project for a multitude of reasons. However, not even the built-in change clause can anticipate every problem. That is why good communication and clear expectations of the parties upfront are essential to minimizing or avoiding risk.

Since most construction projects require performance and payment bonds, signing a contract represents a point of no return: signees are now locked into the terms of that contract, with their business and personal assets at risk. That’s why understanding the owner’s requirements, from budgets to scheduling to quality considerations, is essential to project success.

That’s not to say the contract process is a burden; on the contrary, when executed correctly, contracts should make it easier to process change requests and result in fewer legal worries, not to mention better harmony with the client. Some good online resources for the contract due diligence include the AGC Contract Documents Forum and the AIA library of contract documents.

According to experts, here are 5 best practices for ensuring success with the project:

Eliminate ambiguity around the scope of work and hire an experienced construction attorney to review documents.
Project teams should be on the look-out for indemnity clauses, and in general, attempt to limit such obligations to personal injury and property damage, for which you can secure insurance.
Set aside time to meet with the project manager and superintendent so they understand where a construction company’s exposure hides and what they need to do to protect the company.
Subcontractors need to be mindful of the terms they’re agreeing to, especially as it relates to specific language in a contract. Certain terminology can assign subcontractors more obligations than they’re aware of, particularly when referring to the work performed and materials. Be aware of “termination for convenience” stipulations that can affect a subcontractor’s ability to get paid for work performed if terminated by the GC. Finally, a “time is of the essence” provision gives the contractor the freedom to fire subs if work isn’t performed on-schedule, even if forces beyond the subcontractor’s control were at play.
Provide the necessary protections to keep every team member honest and excited at the prospect of working together.

Being smart about construction contracts can mean the difference between repeat business with a new client or endangering a construction company’s profitability and even solvency.

EE&G Companies, EE&G, mold remediation protocol

February 14, 2020by Olga Loreto Olga Loreto No Comments

What is a Mold Remediation Protocol?

A Mold Remediation Protocol is typically written when items or areas have been identified containing an unacceptable amount or type of mold and a client requires an industry-recognized method of removal or cleaning instructions.

Before a Mold Remediation Protocol is written, a mold assessment is conducted by a qualified Mold Assessor (some States have licensure requirements). The information that is gathered, which includes but not limited to; a site visit, client interviews, room drawings, temperature & Relative Humidity readings, cause & origin, and sampling (where applicable), are used in the report generation.

Though no federal standards have been set for mold remediation, industry guidance and practices have been established. Those are:

The United States Environmental Protection Agency (2001). Mold Remediation in Schools and Commercial Buildings (EPA Publication No. 402-K-01-001). Washington DC: US EPA
American Conference of Governmental Industrial Hygienists (1999). Bioaerosols: Assessment and Control. ISBN: 882417-29-1 Cincinnati OH: ACGIH
New York City Department of Health (2000) Guidelines on Assessment and Remediation of Fungi in Indoor Environments. New York New York: New York City Department of Health
Institute of Inspection Cleaning and Restoration Certification (2003, 2004, 2008). Standard and Reference Guide for Professional Mold Remediation. Vancouver, WA: IICRC S520
American Industrial Hygiene Association (2008). Recognition, Evaluation, and Control of Indoor Mold. Fairfax, VA: AIHA
American Industrial Hygiene Association (2005). Field Guide for the Determination of Biological Contaminants in Environmental Samples. Fairfax, VA: AIHA
American Council for Accredited Certification. CIE, CMI, CMR. Glendale, AZ: ACAC.

Who should have a Mold Remediation Protocol Written?

Any entity that is going to have work performed where mold has been identified either visually or by a qualified Mold Assessor.

What is performed with a Mold Remediation Protocol?

Interview – Review, and discussion with an authorized representative of the Property of current conditions which has led to the claim.

Site Assessment – A physical site assessment of the Property in the area(s) of concern to visually assess the damage(s), retrieve temperature and RH readings, take air and direct samples for mold (if applicable), and gather room dimension to create room/floor drawings to identify the location(s) of concern.

Air Sampling – The purpose of non-viable spore trap air sampling is to provide an approximation of the airborne microbial (fungal) spore concentrations. A minimum of one control sample is typically taken outside the most commonly used entrance into the building, then one or more air samples are collected in the areas of concern within the building. Elevated airborne spore concentrations may indicate an indoor microbial reservoir(s), or that cleaning of personal effects or the HVAC system(s), is a necessary component of a microbial remediation plan.
Direct sampling – The purpose of direct sampling is to identify the type and concentration of microbial spores present on affected materials identified with suspect visible microbial growth. The sampling results are also used for reference for source contamination when air samples are taken.

Non-Scope Items – include visual identification and records review for:

Asbestos-Containing Building Materials (ACM)
Lead-Based Paint
Fire Reduction Chemicals

Qualifications: No federal guidelines exist at this time. However, some states have placed requirements for licensed Mold Assessors and Mold Remediators. For those States that do not have specific requirements, it is recommended that you use a person who:

Has taken a minimum of 24 hours of mold assessment and remediation courses,
Follows one or more of the recognized industry guidelines and practices, and
Acquires, at a minimum, 8 Continuing Educational Units (CEUs) bi-annually.

A person not meeting one or more of those qualifications may assist in the conduct of a Mold Remediation Protocol if the individual is under the direct supervision or responsible charge of a person meeting the minimum qualifications.