Solving Complex Environmental Problems #17 – Forensic Assessment Through Groundwater Dating Negates Remediation

BSTI was hired to assist with a former gas station which has been an open LUST site since the 1980s.  Benzene impacts were present in groundwater and in the Site’s potable well. The client’s scope of work included additional soil and groundwater characterization to be followed by remedial pilot testing and ultimately full-scale remediation. However, BSTIs evaluation of historic and new site characterization data indicated that an adjacent gas station was the probable source of the groundwater impacts. Consequently, BSTI recommended a shift in the scope of work to routine groundwater monitoring along with forensic assessment of on and offsite data to further document the offsite nature of the source.

Forensic assessment of groundwater data included fate and transport modeling as well as evaluation of petroleum constituent ratios. The origin of the potable well impacts was evaluated through the use of groundwater dating. Tracer dating of potable water using chlorofluorocarbons (CFCs) and sulfur hexafluoride (SF6) indicated that potable water was a mixture of older water (pre-1945) and water which recharged around 1980.  This eliminated shallow groundwater in the vicinity of the potable well and rapid short circuiting of the potable well casing as a source of the petroleum compounds in the potable well and was further supportive of an offsite source. Monitoring subsequently documented a rapid (time scale of months) decrease in on site benzene concentrations in response to the first round of in-situ remediation conducted at the adjacent gas station.  This confirmed that petroleum impacts in groundwater at the site originated from this off-site source and that no active remediation to our client’s site was required.

For further information or to talk to BSTI’s Project Manager, contact Tripp Fischer at

Twelve Best Practices to Avoid Pipeline Construction Shutdowns and Fines by Tony Finding, BSTI’s VP and Chief Operating Officer

Tony Finding, BSTI’s VP and Chief Operating Officer authored the article “The Twelve Best Practices to Avoid Pipeline Construction Shutdowns and Fines” which was featured in the NASTT publication Trenchless for Gas Infrastructure.

In this article, Tony identifies some of the more common causes of environmental, regulatory and permit violations that can result in work delays. Please click the link below to read the entire article.

BSTI’s Green Remedy Helps Client Save Money and Avoid Permit Violations at a Wastewater Treatment Plant Spray Irrigation Field

Early Spray Field

BSTI was asked by the operator of a wastewater treatment plant to explore options that would mitigate the diminishing capacity of an existing spray irrigation field. Over time, the diminishing capacity of the spray irrigation field was creating operational issues and exposing the operator to potential violations of their Water Quality Management Permit.

The spray field is an upland deciduous forest with an area covering approximately 12 acres. Infiltration testing carried out by BSTI along with the observance of excess surface runoff indicated that hydraulic loading to the spray field had exceeded its infiltration capacity. Further, a significant population of mature trees within the spray fields died as a result of intolerance of spray field conditions; thereby exacerbating the problem. Because the logistics to simply transfer the excess wastewater to another location was problematic and cost prohibitive, BSTI focused on helping the existing spray field become more effective.

The Solution

BSTI determined that establishing additional vegetation would increase the evapotranspiration rate of the area and improve spray field hydrology.  Several species of shrub willow were identified and selected for further study due to their rapid growth, disease resistance, high yield of leaves and adaptability to a wide range of soil and moisture conditions.

An in-field pilot study indicated that the tested shrub willow species were indeed well suited for the water and soil chemistry conditions that exist in the spray field, and when established have potential average transpiration rates of approximately one inch per week, similar in magnitude to the permitted hydraulic loading rate for the spray field (1 to 3.4 inches per week). BSTI also determined that the survival of any future willow plantings would require the temporary installation of a deer fence enclosure. The enclosure will ensure that the willows planted in the spray field had time to grow to a size resistant to browsing, expected in three to five years, at which time the fence can be removed if desired.

Based on testing conducted by BSTI, gypsum demand across used portions of the spray field varied from 9 to 140 pounds per 1,000 square feet. Given these variable conditions, BSTI conducted a single application of gypsum at 40 pounds per 1,000 square feet prior to planting. This moderate dosing, in line with typical agricultural practices, will improve calcium to sodium ratios, reduce the potential for negative impacts on vegetation from sodium while minimizing the potential for excessive leaching of metals from soil, and potentially improve soil infiltration rates by improving soil structure. 

The full-scale planting of 28,000 willow “stakes” was comprised of the four shrub willow species that exhibited the greatest tolerance to spray field conditions during the pilot study. The four shrub willow species were intermixed throughout the planting zones to avoid monocultures that are more susceptible to disease and pest predation. The target willow planting density was achieved using 9 high density rows of varying lengths (6,000 stems/acre), one willow stake per 7 square feet, with open corridors around spray heads to provide clearance for spray operation and maintenance access. When fully mature these willow species will reach heights ranging between 18 to 25 feet with 2 to 3-inch calipers.

Immediately following the shrub willow planting, BSTI began monitoring willow growth and the integrity of the deer fencing on a bimonthly basis. BSTI is also monitoring spray field hydrology through three soil moisture monitoring stations to establish a baseline of current conditions for comparison to conditions once willows are fully established. 

The Benefit

The high-density willow planting was completed in the spring of 2020 and has returned early positive results. BSTI’s solution to this complex environmental problem has allowed our client to continue to provide wastewater services without fear of permit violation or the high cost of engineered alternatives. Moreover, the once-decaying vegetation in the area will be augmented with a vibrant green landscape.

To learn more about this project, contact Shaun Quinlan at or at (610) 593-5500.  Visit for more information on our capabilities.

How Planning for Projects with Impacted Soils and Materials Can Alleviate Project Delays

If you are in the construction or redevelopment business, you already know how frustrating and costly construction delays can be when unplanned environmental issues arise. The discovery of soils and/or materials impacted with regulated substances can pose a safety concern for workers, shut down tight schedules and throw budgets into chaos. We frequently get calls from construction managers to solve problems that could have been easily managed before all the construction equipment arrived. The purpose of this paper is to help our friends in the construction and redevelopment business anticipate and manage environmental issues as an understood part of the process instead of as a surprise.

Simple up-front planning and development of a cost effective soils management plan can alleviate this common pain point for project stakeholders. The project development team should consider performing valuable and often simple investigations regarding the type and extent of potential soil impacts that may be present. These investigations can provide information that can be favorable to the overall project. Instead of reacting mid-construction (during excavation and off-site disposal of soil), stakeholders may be able to take advantage of regulatory programs such as the PADEP’s Land Recycling Program (Act 2) or other Voluntary Cleanup Programs (VCPs) to potentially leave impacted soils on-site; especially where construction plans enable capping of impacted soils under paved areas. Cut and fill plans can in some cases incorporate impacted soils into the overall balance; allowing for reuse and/or preapproved load and go disposal of impacted soil.

Furthermore, advance knowledge of soils and material conditions can augment an existing soils management plan, reduce risk and enable a site contractor to plan the required Health & Safety (H&S) measures to protect workers and the public. Site contractors may also be required to obtain various OSHA training certificates for personnel including
equipment operators to work at these kinds of facilities.

Another item to consider is fill material. Most states including Pennsylvania have management policy programs to evaluate fill quality. A person or entity placing solid waste onto the ground is generally required to obtain a disposal permit from the PADEP. A person or entity is not required to obtain a permit under the Solid Waste Management Act (SWMA) if they can demonstrate that the material qualifies as clean fill in accordance with the municipal and residual waste regulations. In January 2020, a new Management of Fill Policy was released that provides the PADEP’s procedures for determining whether fill is “clean fill” or “regulated fill”.

Luckily, you don’t need to be an expert in environmental issues to avoid common soil management pitfalls. The experts at BSTI can help you with this planning process.

For more information contact Ethan Prout, P.G. at or (610) 806-5051.

Solving Complex Environmental Problems #14 BSTI’s Ingenuity Saves Client Substantial Costs after a PFAS Release

A client experienced an accidental release of fire suppression foam containing C6 PFAS compounds in one of their facilities and was paying exorbitant fees to emergency response clean-up crews. Aqueous film forming foam (AFFF) was released into floor drains that normally led to the sanitary sewer. In this emergency event, diversion valves were actuated to protect the sewer system and divert the impacted water to an exterior emergency retention basin. Unfortunately, the event happened on a windy day, and as a result the foam was subsequently spread to surrounding areas, including other storm drains that ultimately emptied to a nearby stream. Emergency response included manpower and multiple vacuum trucks to remove the foam from the sewers and stream nearly a ½ mile away. Recovered water was transferred back to the facility and staged in numerous temporary 20,000-gallon storage tanks. After a few weeks, the response footprint was reduced to just the localized sewer system.  However, the client was obligated to continue with recovery efforts on a 24 / 7 basis at costs in excess of $18,000 per day until a permanent solution to the problem was in place.

BSTI was enlisted into this project by one of our partner companies to see if we could design and implement an automated solution to the costly manual water collection program.  Within less than 24-hours of visiting the site, we responded with a solution for an automated recovery system designed to remove the expensive vacuum trucks offsite as soon as possible. Because of our remediation experience and can-do attitude, we were able to procure, fabricate and deploy recovery pumps and control systems within days.  Measures were also implemented to reduce/prevent storm water from being introduced into the affected sewer network which lessened the volume of impacted water being containerized. Within less than one week of system deployment, the client was able to remove the manual crews and vacuum trucks from the site. The immediate benefit to the customer is that they now have a reliable automated recovery system in place for the same cost of just two days of vacuum trucks.

BSTI was subsequently asked to design and operate a treatment system for the containerized PFAS-containing water.  That, however, will be the subject of another installment of Solving Complex Environmental Problems.

If you have questions about this subject and wish to contact us, contact Tony Finding at

Solving Complex Environmental Problems Post #12, Keeping Well-Informed with Dynamic Regulatory Changes Helps Client and Project Succeed

The Problem

A multi-unit residential building in an urban setting was in the process of being purchased in a real estate transaction. A review of historic environmental reports and documents identified a former underground heating oil storage tank (UST) that existed under the basement concrete slab. The UST was closed-in-place, but historic investigation and soil sample analyses verified the presence of heating oil-related impacts at levels above regulatory limits for residential properties in soils at the site. 

Due to the concentrations of heating-oil compounds detected in soils, the site would have had to ultimately enter the state’s regulatory cleanup process. To navigate this process, BSTI developed a comprehensive field investigation for defining the extent and degree of apparent impacts to soils. What further complicated matters was the excessive depth (> 17 feet) of impacted soils in a basement with limited access and overhead space. Structural evaluation, confined space work and probable shoring of the future excavation and sampling area would be necessary and expensive.

The Pivot

Prior to implementing the remedial investigation and regulatory notifications, BSTI scientists proficient in the state’s regulatory process thought to investigate if any rule changes were possibly forthcoming.  We were pleasantly surprised when we identified a very recent update to the state’s voluntary cleanup program that applied to our project. Specifically, a public bulletin from two weeks prior contained a proposed increase in the residential medium specific concentrations (MSCs) for the two (2) heating-oil compounds that were problematic at our site.  After verifying the proposed changes and the rule making process with the regulatory agency, BSTI generated a professional opinion that summarized these significant changes and provided expert guidance to the stake holders.  The result was that no further action would be necessary should the promulgation of the new MSCs go into effect.  BSTI also provided rationale based on the where the proposed MSCs were in the rule making process that added comfort that the new MSCs would likely be adopted.

The Benefit

By wisely evaluating historical documents, current regulatory and project conditions and knowledge of future regulatory changes on the horizon, BSTI was able to swiftly bring about the best possible outcome for the client, project stakeholders and real estate transaction without additional characterization, remediation and environmental closure activities. Overall, BSTI saved the client over 90% of projected total costs by finding a desirable “off-ramp” for the stakeholders on both sides of the transaction. In addition, the total expected time to bring closure to the site was reduced by possibly as much as 6 to 12 months. While discovery of historical environmental liabilities is alarming, BSTI’s practical approach to the project, familiarity with the state’s regulatory framework and promulgation of proposed regulations and pro-active strategic planning, the historical impacts were favorably resolved for our client with no lingering post-closure responsibilities. BSTI’s Project Manager for this project is Ethan Prout, P.G.  Ethan can be contacted at  Visit for more information on our capabilities.

Solving Complex Environmental Problems Post #7 Astute pivot in remedial strategy saves client significant time and money

The Problem

An office building owner switched their fuel source from heating oil to propane resulting in the removal of their 1,000-gallon heating oil underground storage tank (UST). As excavation of the UST proceeded, signs that the tank had been leaking became evident. The unearthed steel tank showed holes and pitting from corrosion. Stained soils, oily residue and strong odors were discovered. In addition, standing water with a heavy oily sheen was observed within the excavation trench, prompting a regulatory reporting event. Sample analysis verified the presence of heating oil-related impacts at levels above regulatory limits for commercial properties in both soils and water.

Due to the levels of target compounds detected in soils and water, the site entered the state’s regulatory cleanup process. To navigate this process, BSTI developed a comprehensive field investigation for defining the extent and degree of apparent impacts to soils and groundwater. During the assessment however, BSTI geologists determined that the water observed within the tank excavation was not, in fact, groundwater. Rather it became clear during well drilling that the water in the excavation was a localized feature, and the actual shallow water table resided much deeper.

Soil was removed to a point below the contamination level

The Pivot

Based on the information obtained in the field, BSTI realized that we could shift cleanup strategies to take advantage of a streamlined regulatory process when dealing with only soil impacts related to tank releases. BSTI could expedite closure for the site if it could be shown that soils had been remediated, groundwater was not adversely affected, impacts did not migrate offsite, and the cleanup process was completed within three months of the release discovery. To pursue this cleanup option, BSTI fast-tracked a soil excavation and disposal scope and completed the regulatory documentation within days of the three-month deadline. Ultimately, cleanup targets were achieved, and the site received full liability protection for the release without any restrictions to future intended site use.

The Benefit

By astutely connecting field observations and knowledge of the regulations, BSTI was able to rapidly shift the remedial strategy to bring about the best possible outcome for the client. Overall, BSTI saved the client over 50% of projected total costs by taking advantage of the streamlined cleanup process. In addition, the total expected time to bring closure to the site was reduced by as much as two years. While discovery of a leaking tank is alarming, due to BSTI’s sound technical approach, familiarity with the regulatory framework, and pro-active strategic planning, the release was quickly and favorably resolved for our client with no lingering post-closure responsibilities.

Solving Complex Environmental Problems #5 Anti-Fouling Agents to Reduce O&M Costs and Increase LNAPL Recovery

BSTI was the provider of in-situ remediation services for a large-scale subsurface release of diesel fuel at an electrical generating station. Water table depression pumps were installed in four large-diameter recovery wells to control the migration of diesel fuel and to create a cone of capture in the aquifer to promote LNAPL recovery. BSTI personnel had learned over many years of LNAPL recovery projects that a steady and consistent aquifer drawdown is critical to both effective aquifer control and LNAPL recovery. Like many remediation systems, this one experienced severe inorganic and organic fouling in the water pump intakes, piping, and meters causing an increasingly diminished ability to move water and maintain the desired aquifer drawdown.

The initial (and typical) response was to shut down the system and perform maintenance that included pump disassembly and cleaning, water pipe cleaning and replacement and flow meter cleaning. Such maintenance was needed every two weeks and quickly became ineffective and inefficient.

Above: White aluminum oxide deposits on water pump

Field personnel noticed an inconsistency in the fouling problem across the four recovery wells and was able to link it to the existence of a large coal pile at one end of the project area.  Fouling was primarily caused by aluminum oxide and iron related bacteria but to a varying degree based on the proximity to the coal pile.  Because water chemistry was a strength, BSTI personnel and a specialty vendor were able custom design an in-field application of anti-fouling agents on an individual recovery well basis. The anti-fouling agents had to be custom formulated to be effective and compliant with State-mandated restrictions on the use of phosphate-based chemicals that could be introduced into the waterways of the State.

Above: Downhole view of recovery well.  Fouling control tubing is middle left.

BSTI then designed a simple delivery system for the anti-fouling agents to maximize effectiveness and minimize chemical costs.  Field staff set up automatic metering pumps at each recovery well to deliver the anti-fouling agent through tubing directly to the water pump intakes; thereby maintaining the proper dosage without overdosing the well and unnecessarily increasing chemical costs.  The cost for anti-fouling system was $32.00 per day for each recovery well.

Such a little step contributed to big results.  The shutdowns and maintenance associated with fouling control decreased from twice monthly to twice annually. O & M costs were reduced from greater than $65K per year for manual cleaning to less than $30K per year for the anti-fouling system.  More significantly, the anti-fouling system allowed the overall water table depression system to remain operational for long period of time (98% uptime); providing a consistent aquifer drawdown, effective aquifer control and maximum LNAPL recovery.  Over a period of ten years of system operation, $350,000 were saved and 385,000 gallons of LNAPL were recovered.  The project has since met all regulatory requirements and the remediation system has been dismantled.

For more information, contact Tony Finding at

Solving Complex Environmental Problems #4: Using Cutting Edge Science to Avoid Ongoing Remediation

BSTI uses a science-based approach to close a site with LNAPL, save our client money and re-start a stalled real estate transaction.

The Problem

A release from a 30,000-gallon underground storage tank resulted in a body of diesel fuel above and below the water table (commonly referred to as light non-aqueous phase liquid or LNAPL).  This condition created a regulatory compliance problem, a financial burden on the property owner and severely complicated a planned real estate transaction.

Based on a thorough site characterization, BSTI determined that potential mobility of the LNAPL body would be the primary driver to achieving closure with the regulatory agency.  A traditional approach was first adopted that used a product recovery pump to actively remove available LNAPL from the subsurface.  During the recovery process, BSTI tracked recovery rates, in-well liquid levels, and assessed the efficacy of the system.  After several months, diminished returns of product recovery had been established and dissolved contaminants in groundwater remained below screening criteria at downgradient and perimeter monitoring wells. Despite establishing a technical argument for the cessation of LNAPL recovery, the regulator initially requested that additional recovery efforts be deployed based on an antiquated and unscientific “rule of thumb” cleanup criteria of reducing LNAPL thickness to less than 1-inch.  LNAPL thickness has been the prevailing regulatory criteria for the past five decades and remains the closure criteria on the majority of LNAPL cleanup projects.

The Solution

Rather than accede to the regulator’s request for additional LNAPL remedial measures, BSTI employed a science-based approach to clearly establish that the LNAPL remaining at the Site presented an insignificant exposure risk to human health and the environment. Using data collected from the site, as well as following recently developed technical guidance (1), BSTI developed a sound LNAPL conceptual site model (LCSM). The LCSM utilized multiple lines of evidence, including a LNAPL Transmissivity analysis, showing that recovery efforts had indeed reached the point of diminished returns and additional remedial efforts were unlikely to appreciably diminish the remaining LNAPL body at the site. Moreover, an exposure pathway analysis revealed no direct link between the LNAPL and potential receptors. Through the development of a LCSM for the site, BSTI demonstrated an acceptable level of risk for the LNAPL remaining at the site which would avoid a potentially costly and enduring process of continuing to apply additional remedial measures.

BSTI’s request for closure was approved by the regulator and liability relief was granted to the client.

Benefits to the Customer

By avoiding the additional active remediation at the site, BSTI saved its client from venturing into a costly cleanup with an unclear endpoint. Due to the scientific demonstration of a non-mobile LNAPL body at the site and the low levels of dissolved COCs in groundwater, the site was able to be closed by attaining generic cleanup standards. As a result, the client was relieved of adherence to a long-term care and monitoring plan, a deed restriction, or an environmental covenant.  The planned sale of the property took place without lingering environmental concerns.

Illustration of the conceptual release model showing the directional plume of the petroleum release and the location of the primary monitoring well.

For more information, contact Tripp Fischer at .

  • (1) The Pennsylvania Department of Environmental Protection’s Revised Land Recycling Program Technical Guidance Manual (TGM) was finalized on January 19, 2019. The TGM provides guidance for implementing the Chapter 250 regulations promulgated pursuant to the Land Recycling and Environmental Remediation Standards Act (Act 2 of 1995). The current TGM includes valuable guidance on defining the removal of LNAPL to the Maximum Extent Practicable (MEP). The LNAPL guidance in the TGM is based in large part on the Interstate Technology & Regulatory Council’s (ITRC) LNAPL Team publications and trainings ( ASTM’s LNAPL Transmissivity Guidance (E2856), and ASTM LCSM Guide (E2531).  BSTI’s Vice President and Principal Hydrogeologist Tripp Fischer, P.G. served as co-chair on this ITRC committee, is a trainer for the ASTM LNAPL Transmissivity Standard, and continues to provide training to regulatory bodies on the topic.

BSTI gets physically challenged people up and moving on adaptive exercise equipment

BSTI’s major charity contribution this year was to the IM Able Foundation. The mission of the IM ABLE Foundation is to remove obstacles that prevent people affected by disabilities from being physically active. Recently IM Able organized a competitive duathlon race in Wyomissing PA as one of their annual fund raising events. A duathlon combines running and bicycling. The event also had a category for physically challenged athletes to compete on adaptive equipment, many of which was donated to them by the IM Able Foundation. Before the race started, Chris Kaag, founder of IM Able and an adaptive athlete himself, presented recumbent tricycles to two grant recipients. BSTI’s contribution went directly toward the purchase of this adaptive equipment. Here are some photos of the presentation and the adaptive athletes in action:

Chris Kaag, Founder of IM Able, presents adaptive equipment to grant recipients
The adaptive athletes started the race first
One of the grant recipients out on the course
Another grant recipient