Category: LandWatch

Mochi and Terradex’s Long Term Stewardship Mission

The excavation limits of a new water main are marked on the street. Consistent with state regulation, the excavator calls in the excavation limits to the One-Call System. Soon the street is marked with utility locations. Surprisingly, the excavator receives a fax describing that the excavation site as occurring in a zone of environmental contamination. The responsible party who faxed the notice of contamination is pleased to have averted a hazardous substance release and to have protected the excavators and the public from harm. The excavator, however, is not pleased; their fixed bid did not anticipate the cost of handling contamination and work delays.

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Bob Wenzlau January 29, 2021 0 Comments

NAESIP and Terradex Introduce Brownfield Loss Control Services

In October 2005, Bob Wenzlau of Terradex was appointed Task Group Chair to build a practice standard for Landowner Continuing Obligations. When complete, the practice standards will systematically improve the long-term public and environmental safety at brownfields while limiting financial liabilities brownfield redevelopers. The Task Group includes participation from USEPA, state government, brownfield redevelopers, environmental professionals and legal counsel.

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Bob Wenzlau April 13, 2016 0 Comments

DigClean is Protecting Excavators Across Delaware From Buried Chemicals

Excavations are a common event around contaminated sites as each flash of light signifies.  This map shows flashes for each excavations around contaminated sites in New Castle County, Delaware.  Try  adjusting the map, the date may be adjusted on the slider, and the coverage area adjusted by the zoom control.  

You are watching about 3,500 excavation clearances resulting in over 1,000 advisories automatically sent to excavators by Terradex’s DigClean service. Terradex’s client since 2012 is Delaware Department of Natural Resources and Environmental Protection (DNREC).  A one minute video overviews how the excavation clearance system can not only protect buried pipelines, but also convey health and safety information to workers about to dig.

Construction excavations threaten remedies, breach institutional controls, create circumstances where contaminated soils are mismanaged, and introduce health hazards to construction workers.  The value of DigClean is to bring tangible information to excavators so that they can make timely, smart decisions to control these threats.  Avoiding chemical contamination in the field is manageable once DigClean transmits an advisory.

The advisory provides links to general soil management plans, but can also provide a link to a site-specific soil management plan. There are also links to NIOSH Pocket Guide and Agency for Toxic Substances and Disease Registry (ATSDR) Toxic Substances Portal for chemical specific hazard information. The NIOSH Pocket Guide to Chemical Hazards is intended as a source of general industrial hygiene information for workers, employers, and occupational health professionals, while ATSDR provide guidance to non-work related public exposure scenarios. For  a spill containing benzene, the respective chemical links in the advisory would include:a NIOSH benzene link and a ATSDR benzene link.

The flow of an excavation ticket from the excavator, through the excavation clearance system, Terradex and DNREC, and then back to the excavator with an advisory.

An excavator makes an obligatory 811 telephone call to provide 48-hours advance notice of an excavation.  The excavator provides the location, description, timing as well as contact information.  The excavator’s provided contact information may be a phone, fax or email address.   The excavation center upon receiving the incoming notice from the excavator will only forward those excavation notices to Terradex that are near contaminated sites (as mentioned below, the locations of the sites were provided in setup of the program).  Terradex provides an additional geographic screening after receiving the incoming notice. For the sites within 50 feet of a contaminated site, an excavation advisory is transmitted to the excavator.   The advisory is sent via email, SMS text or fax depending on the contact information originally provided. The excavator is directed to followup with DNREC when there are questions.

At the beginning of the DigClean in Delaware, the excavation clearance center was provided with a GIS map prepared by DNREC with the boundaries of contaminated sites.  If a extent of contamination was not known, the parcel boundary around the contaminated location is used instead. As DigClean operates, DNREC uses DigClean’s web management console to view the advisories transmitted, and those excavations where based on a distance evaluation an advisory was not transmitted.  DNREC can choose to override the distance screening, and send an advisory.

Terradex developed an analysis of California excavations near sites with institutional or engineering controls. The California analysis  revealed a correlation between urbanization, the area of the impacted site and the frequency of excavation.  This analysis in Delaware complements the California analysis by visually presenting the DigClean service as it expands within Delaware. The DigClean service is also provided to Idaho, West Virginia and California.

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Bob Wenzlau November 22, 2014 0 Comments

Long Term Stewardship at Vapor Intrusion Sites – Looking at the End Game

Long term stewardship (LTS)  is the “end game” of any vapor intrusion problem. Any smart player, considers the “end game” at the start and during play. Knowing the “end game” sets a smart direction for any stakeholder of a vapor intrusion – a responsible party, landowner, environmental agency staff, and the public.

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Bob Wenzlau March 18, 2014 0 Comments

Forecasting an Engineering Control or Institutional Control Breach, A Study of Third-party Excavation Activity

Excavations by third-parties are inevitable near any cleanup site. Of concern to cleanup site managers, these unexpected events can breach institutional or engineering controls relied upon in a site’s cleanup remedy. Third-party excavators include utility companies, developers and contractors whose work is not part of the site cleanup process.

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Bob Wenzlau September 25, 2013 0 Comments

Terradex Gains GSA Contract Vehicle to Serve Federal Clients

Terradex, a unique and pioneering provider of information-based long-term stewardship (LTS) services, is pleased to announce its award of U.S. General Services Administration (GSA) Schedule 899 Contract for Environmental Services (Contract number GA-10F-009AA).

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Bob Wenzlau December 19, 2012 0 Comments

Off-site Groundwater Plumes – Terradex LandWatch Is A Risk Manager’s Best Friend

Groundwater contamination plumes often migrate off-site beyond the site where the chemicals were released.   The fate of the off-site plume poses a vexing risk management challenge for the regulator, potential responsible parties and even affected local governments. Terradex’s LandWatch is an efficient and effective adjunct to the risk management plan for an off-site plume.

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Bob Wenzlau May 3, 2012 0 Comments

USEPA Issues Policy Guidance on Evaluation of Institutional Controls

The USEPA released on September 13, 2011 new guidance titled “Recommended Evaluation of Institutional Controls: Supplement to the Comprehensive Five Year Review Guidance”  providing recommendations for the monitoring and inspection of ICs during the CERCLA five-year review process.  The new USEPA guidance recommends that “ICs be mentioned specifically in the overall protectiveness statement when long-term protectiveness hinges on compliance with ICs.”

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Bob Wenzlau September 23, 2011 0 Comments

Terradex Keeps Contaminated Soil Safely Managed

No activities that will disturb the soil at or below the pavement in the restricted Areas (e.g., excavation, grading, removal, trenching, filling, earth movement, or mining) shall be allowed on the Property without a Soil Management Plan and a Health and Safety Plan.

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Mike Sowinski September 15, 2011 0 Comments

Financial Health Monitoring of Institutional Control Property Owners

The long term success of Institutional Controls (ICs) and cleanup remedies is often only as strong as the financial health of new property owners.   This is why, along with its classic suite of land monitoring, Terradex LandWatch now monitors the financial health of contaminated property owners.

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Bob Wenzlau September 3, 2011 0 Comments
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