Skip directly to: content | left navigation | search
  1. Home ›
  2. Chemical Weapons Elimination ›
  3. Reports and Publications ›
  4. VX Report Table of Contents ›
  5. General Overview

General Overview

    Report for Congress: Review of the U.S. Army Proposal for Off-Site Treatment and Disposal of Caustic VX Hydrolysate From the Newport Chemical Agent Disposal Facility

    April 6, 2005

    Background

    The U.S. Army is proposing a plan for destroying their stockpile of VX,* a nerve agent developed for use in chemical warfare. The proposed plan is a two-step process involving the treatment, transport, and disposal of the VX and its byproducts.

    The stockpile (1,269 tons in 1,690 containers) is currently being stored at the Newport Chemical Agent Disposal Facility in Newport , Indiana . The first step of the proposed process will take place at this facility, where the VX will be mixed with water and sodium hydroxide. The mixing will result in a waste product referred to as caustic VX hydrolysate (CVXH).

    The second step is to transport the CVXH to another location, the DuPont Secure Environmental Treatment Chamber Works Facility in Deepwater, New Jersey . The DuPont facility will further treat the CVXH waste and then discharge this final waste product into the Delaware River .

    The Army’s proposal has raised concerns about the possible effects on public health and the environment. Several members of Congress asked the Centers for Disease Control and Prevention (CDC) to evaluate the Army’s proposal. CDC, in turn, asked the U.S. Environmental Protection Agency to review the ecologic risks associated with disposal of the treated CVXH in the Delaware River.

    Critical Issues of Concern

    CDC identified several critical issues that need to be addressed. Following are the concerns and a summary of CDC’s evaluation.

    The potential health hazards associated with the waste (CVXH) produced at the Newport facility.

    The potential human health hazards of the untreated CVXH waste are mostly associated with its highly corrosive and caustic properties. Although negligible levels of VX and EA 2192 (a degradation product with nerve-agent properties) may be present, these small amounts are not considered potential hazards to human health. The toxicity of CVXH does not rule out handling and transport if proper precautions are taken (for example, using personal protective equipment).

    The ability of a) the Newport facility to produce CVXH that meets the established clearance criteria and b) the DuPont facility to adequately treat the CVXH.

    The Newport facility used two chemicals (referred to as stabilizers) to prevent the breakdown of VX: diisopropylcarbodiimide (DIC) and dicyclohexyldicarbodiimide (DCC). 

    CVXH produced with DIC-stabilized VX at the 8% agent loading level should meet the Army’s clearance criteria for VX and EA 2192, and it can be treated at DuPont. The term “loading” refers to the initial percentage of VX added to the Newport reactor before the reaction takes place.

    Loadings greater than 8% of DIC-stabilized VX or any treatment of VX stabilized with DCC are not recommended until treatment effectiveness is demonstrated and confirmed. Consequently, less than one half of the Newport VX stockpile currently can be processed to meet clearance criteria.

    The potential risks associated with transporting the CVXH from Indiana (from the Newport facility) to New Jersey (the DuPont facility).

    The proposed transportation plan meets Department of Transportation (DOT) regulations, and precautions in the proposed plan will adequately protect the public and personnel.  DOT assisted in the transportation review.

    The potential ecologic impact associated with disposal of the DuPont-treated waste material into the Delaware River.

    EPA does not have enough information to say whether the ecologic risk from the discharge of treated CVXH into the Delaware River is acceptable.  In addition, EPA is concerned that the clearance criteria for VX in CVXH (20 parts per billion) is based only on protecting humans and may not protect aquatic organisms.

    Conclusions

    CDC found that the Army’s proposal sufficiently addressed critical issues in the areas of potential human toxicity, transport, and treatment of CVXH. EPA concluded that the information about the ecologic risk associated with discharging the treated CVXH into the Delaware River is inadequate.

    Therefore, CDC cannot recommend proceeding with the treatment and disposal at the DuPont facility until EPA’s noted deficiencies are addressed. 

     

    * VX: agent O-ethyl S-[2- (diisopropylamino) ethyl] methyl phosphonothioate.