Remedial safety in in‐situ chemical oxidation, crucial to success

Abstract

In-situ chemical oxidation (ISCO) has been developed as a remedial technique for several decades, implemented under a variety of Health, Safety & Environmental practices. A positive safety culture and implementation of best practices are important for the protection of all workers, as well as the general environment and the public, and for compliance with regulatory requirements and professional workplace expectations and ethical obligations. ISCO is arguably one of the highest-risk approaches for in situ remediation, and the consequence of poor safety practices, lack of training, and a failure to sharing previous knowledge can be substantial. Since 2000, the remediation industry has experienced step changes in the evolution of safety practices, shifting focus from a centralized autocratic planning process, toward a behavior-based safety-first individual empowerment, resulting in-"I am responsible for the safety of myself and the team." Supporting this step-change, this paper explains the need for safety-first work practices, provides examples of common inadequate or incomplete practices, discusses the top four adverse incidents in ISCO projects (impacts to storm sewers; impacts to other utilities; errors and omissions; and inadequate contingency planning), and provides a description of the top three skills to mitigate risks (planning, executing, and correcting).

A Critical Review of the Modelling Tools for the Reactive Transport of Organic Contaminants

“…ISCO is a flexible cost-effective method that can be applied to light and dense recalcitrant hydrocarbons such as aromatic hydrocarbons [306,307]. As with other remediation techniques, there are several challenges with ISCO, including optimal estimation of dose rate [290,308], accurate injection [309,310], ensuring safety [311,312], and modelling, as few modelling tools are currently available [299,313,314]. ISCO was modelled using the computer code ISCO3D, which was adapted to simulate the oxidation of chlorinated hydrocarbons by permanganate [296], MITSU3D, and modified MIN3P to mimic the movement of permanganate in the 3D domain and under variable flux density [315]; DNAPL3D-RX simulated reactions between potassium permanganate and chlorinated ethenes [316], CDISCO, and CORT3D, and was developed as a decision support tool for permanganate oxidation planning [297,299,317].…”

A PHREEQC-Based Tool for Planning and Control of In Situ Chemical Oxidation Treatment

“…The ISCO process still needs to be tested, improved, and provided with practical guidelines [20][21][22] as the precise, almost surgical injection of the liquid and the accurate estimation of the oxidant dose at the time of use, as well as the rebound effect and the loss of oxidants due to reactions with the groundwater matrix [19,[23][24][25], represent a real challenge. As the process is very dynamic and invasive, its control is also a problem [26].…”