These amendments to 6 CCR 1007-3, Parts 261 and 268 are
made pursuant to the authority granted to the Solid and Hazardous Waste
Commission in §
25-15-302(2),
C.R.S.
Addition of K903 (Hydrolysate) Listing
Introduction
These proposed amendments create a new hazardous waste
listing for mustard agent hydrolysate to accurately reflect its chemical
hazard. Hydrolysate is the aqueous waste resulting from the chemical
neutralization, or "hydrolysis," of Mustard Agent (K901) with the addition of
copious amounts of water. Hydrolysate is a waste derived from the treatment of
mustard agent that currently carries the existing K901 or K902 specific source
hazardous waste listings for military munitions. Under the K901 or K902
hazardous waste listings for chemical weapons, any treatment residue of mustard
agent, or any water contaminated through contact with mustard agent, is
considered an acute hazardous waste (Hazard Code H), mandating restrictive
regulatory requirements. The acute hazardous code associated with the military
munitions waste listings is due to the presence of mustard agent, which is a
carcinogen, mutagen and teratogen and capable of causing human health impacts
at low concentrations. However, analytical characterization data as well as
technical information for the mustard agent neutralization process that has
recently become available indicates that once neutralized, and subsequently
stabilized by increasing the pH of the derived waste to a sustained level
greater than 10, hydrolysate waste no longer contains detectable concentrations
of the agent. These amendments therefore propose to create a new listing for
the hydrolysate waste, K903 that does not include the acute hazardous waste
code. The new non-acute listing for this waste will allow for more regulatory
flexibility in storage, treatment and management of the waste, and also ensure
that the chemical hazard of the waste is properly designated during any
subsequent transportation to a permitted treatment, storage or disposal
facility.
Previous rulemakings for the K901 and K902 waste listings
for mustard agent wastes (See 6 CCR 1007-3, § 8.46 and § 8.72)
established the underlying basis for the listings which also include several
other hazardous waste constituents in addition to mustard agent. These
underlying hazardous waste constituents (UHCs) are present in the original
agent due to manufacturing impurities or chemical degradation byproducts. While
no mustard agent remains in the neutralized hydrolysate, the waste still
retains diluted concentrations of UHCs that must be properly treated before the
waste may ultimately be disposed of in a hazardous waste landfill.
Additionally, the previous amendments to the K901 and K902 listings
inadvertently included two hazardous waste constituents in the mustard agent
waste that are not in it, and omitted two other constituents that are present
in it at its point of generation. These amendments therefore also propose to
add a land disposal restriction treatment standard for the K903 hydrolysate
waste that retains Part 268 land disposal restriction treatment standards for
all the UHCs present in the waste, including the two additional UHCs contained
in it, to ensure it is properly treated prior to land disposal. The proposed
amendments would also add the two additional constituents to the existing K901
and K902 listings in Part 268, and would remove the two inadvertently included
constituents from the listings.
Specific Regulatory
Amendments
The Colorado Department of Public Health and Environment,
Hazardous Materials and Waste Management Division (the Division) is proposing
the following amendments to 6 CCR 1007-3:
1) Addition of a hazardous waste listing,
K903 for hydrolysate, defined as the waste generated from the chemical
neutralization of Mustard Agent with water, to the list of hazardous waste in
Section 261.32 - "Hazardous Waste from Specific
Sources" - Military Munitions
2) Addition of Hydrolysate to Part 261
Appendix VII - "Basis of Listing Hazardous Waste" for
proposed K903 listing
3) Addition
of a treatment standard for K903 hydrolysate waste generated from mustard agent
(HD and HT) contained in all three configurations of munitions, including
105mm, 155mm, and 4.2 inch mortars to Part 268.40
following the point in the neutralization process
where the hydrolysate is manipulated to a sustained and stable pH of greater
than 10,
4) Removal of two
hazardous constituents from the basis for the K901 and K902 hazardous waste
listings, 1,4-dichlorobenzene and 2,4,6-trichlorophenol, from Parts 261,
Appendix VII, and 268.40 that are not present in the mustard agent and that
should not have been included in the original listings.
5) Addition of two hazardous constituents to
the basis for the K901 and K902
hazardous waste listings, chloroform and
hexachloroethane, to Parts 261, Appendix VII, and 268.40 that are present in
the mustard agent and that should also be included in the original listings.
Mustard Agent Neutralization and Chemical
Analysis of Hydrolysate
The Department of Defense and U.S. Army are currently
pursuing treatment and destruction of over 750,000 waste chemical weapons
stored at the Pueblo Chemical Depot (PCD). The chemical weapons inventory is
composed of 105mm and 155mm projectiles and 4.2 inch mortars that contain over
2600 tons of mustard agent (HD and HT). The Pueblo Chemical Agent-Destruction
Pilot Plant (PCAPP) Facility is currently under construction at PCD and will be
used to safely dismantle the weapons, access the mustard agent inside them, and
treat the agent by neutralizing, or hydrolyzing, it with water. The resulting
waste, or hydrolysate, will then be subsequently treated at PCAPP in biological
treatment units to eliminate the primary breakdown product of the mustard
hydrolysis reaction, thiodyglycol. Thiodyglycol is a schedule 2 chemical
compound that must also be destroyed with the mustard agent in accordance with
the international Chemical Weapons Convention. Once treated, the hydrolysate or
water waste will be sent through a crystallizer and brine reduction system
on-site to separate and remove metal salts, with the treated effluent then
recycled back into the mustard neutralization process.
Mustard agent hydrolysis will occur in tank reactors at
PCAPP and will be closely monitored to ensure for complete destruction of the
mustard agent. Recently, treatability studies were completed at Battelle
Laboratories in West Jefferson, Ohio on samples of the two different types of
mustard agent found in the stockpile of weapons at PCD (HD and HT). The purpose
of the treatability studies was to ensure that the planned recipe and
parameters for treatment of the mustard will be effective in destroying the
Pueblo agent and also to obtain a detailed chemical analysis of the resulting
hydrolysate. Hydrolysis of the mustard agent was completed in the same manner
it will be performed at PCAPP under the treatability studies, which essentially
involves mixing the mustard agent rigorously with water at a ratio of 1:8, and
then subsequently bringing up the pH of the mixture with sodium hydroxide to a
sustained and stable pH greater than 10. Retention of the treated mixture at
the sustained and stable pH greater than 10 is necessary to completely destroy
breakdown products of the mustard agent, including sulfonium ions that can
still cause blistering effects and that also may readily revert back into
mustard agent.
The analytical results for the hydrolysate generated during
the treatability studies demonstrated that the Pueblo agent will be
successfully neutralized by hydrolysis. No detectable concentrations of mustard
agent (HD or HT) were identified in either of the hydrolysates, indicating that
both types of mustard agent will be completely destroyed. Detailed chemical
analysis of the hydrolysates resulting from the treatability studies did
however show detectable concentrations of several other hazardous waste
constituents. While many of these constituents were diluted to very low
concentrations with the water used in the hydrolysis process, a few of the
constituents remained at concentrations above toxicity characteristic levels.
Further analysis of these results indicates that none of the hazardous waste
constituents remaining in the hydrolysate were present at levels which would
cause the waste to be considered an acute hazardous waste in accordance with 6
CCR 1007-3, Section 261.11(a)(2).
Hydrolysate is a waste derived from the treatment of
mustard agent that has been chemically altered to eliminate the mustard agent
contained in it. The results of the treatability study therefore support
listing of this hydrolysate waste with a new K903 listing that does not retain
the acute hazard code, but retains the toxicity code in accordance with 6 CCR
1007-3, Section 261.11.
Regulatory Analysis
Creation of a new non-acute hazardous waste listing (K903)
for mustard agent hydrolysate will allow for greater flexibility in managing
this waste at PCAPP once it is neutralized and analytically verified to be free
of agent downstream of the hydrolysis reactors. In particular, the new
non-acute listing for hydrolysate will allow larger volumes of any newly
generated wastes that may come in contact with the hydrolysate to also be
managed as non-acute hazardous waste. This flexibility is significant in that
up to 55 gallons of non-acute waste may be accumulated in a satellite
accumulation area before it must be removed, whereas acute hazardous waste may
only be accumulated up to one quart in a satellite area before it must be
removed. Triple rinsing of containers holding hydrolysate wastes will not be
required under the new waste listing because they will not be considered acute.
Finally, the new listing would also ensure that the correct hazard code is
reflected on the manifest for the waste in the event an accident occurs during
transport.
In accordance with 6 CCR 1007-3, Section 268.3(a), the
dilution prohibition states that a hazardous waste cannot be diluted in any way
as a substitute for adequate treatment to achieve compliance with the land
disposal restriction standards. Accordingly, the basis for hydrolysate listing
and the new treatment standard for it ensure that all the hazardous waste
constituents originally present in the mustard will be properly treated prior
to land disposal. Mustard hydrolysate is not a newly generated waste, but
rather a mustard agent waste that has been chemically altered to destroy the
agent. While effective in destroying the mustard agent, the hydrolysis process
is not effective at treating all the underlying hazardous waste constituents
that were originally present in the waste mustard. Since UHCs in the mustard
largely become diluted in the hydrolysate, retention of the hydrolysate as a
hazardous waste subject to treatment requirements for any UHCs contained in it
will ensure the dilution prohibition for this waste is not violated.
Impact of Proposed Listing and Treatment
Standard
A new non-acute mustard hydrolysate listing will allow for
more regulatory flexibility in managing this waste which no longer contains
mustard agent. Currently, the only facility in Colorado known to possess large
quantities of mustard agent is PCD and the only facility that may generate
large quantities of mustard hydrolysate is PCAPP. Site-wide clean-up of the
Rocky Mountain Arsenal is near complete and future management of any mustard
agent or hydrolysate at RMA is not expected. PCD is owned and operated by the
United States Army, which also is an owner of PCAPP with the Department of
Defense. Small quantities of mustard agent may be discovered at other former
military training facilities in the future, but it is not likely that large
quantities of agent will be found. In the event mustard agent is neutralized
during such a discovery, and mustard hydrolysate is generated in accordance
with the new hydrolysate listing, these other military facilities may utilize
the flexibility created by the new hydrolysate listing. Finally, in the event
the mustard agent hydrolysate cannot be successfully treated at PCAPP, the
waste may be shipped off-site to another permitted hazardous waste treatment,
storage or disposal facility that may also manage the waste in accordance with
the new hydrolysate listing.
Commission Finding
The Commission has evaluated the information presented at
the rulemaking hearing, as well as the information in the Statement of Basis
and Purpose. The Commission finds that this rule is necessary to protect the
public health and the environment of the state.
Statement of Basis and Purpose - Rulemaking Hearing
of February 19, 2013
Notes
6 CCR 1007-3-8.80
37
CR 24, December 25, 2014, effective 3/2/2015
38
CR 11, June 10, 2015, effective 6/30/2015
39
CR 05, March 10, 2016, effective
3/30/2016
39
CR 11, June 10, 2016, effective
6/30/2016
40
CR 06, March 25, 2017, effective
4/14/2017
40
CR 11, June 10, 2017, effective
6/30/2017
40
CR 21, November 10, 2017, effective
11/30/2017
41
CR 06, March 25, 2018, effective
4/14/2018
41
CR 11, June 10, 2018, effective
6/30/2018
41
CR 24, December 25, 2018, effective
1/14/2019
42
CR 06, March 25, 2019, effective
4/14/2019
42
CR 06, March 25, 2019, effective
5/30/2019
42
CR 11, June 10, 2019, effective
6/30/2019
43
CR 12, June 25, 2020, effective
7/15/2020
44
CR 06, March 25, 2021, effective
4/14/2021
44
CR 11, June 10, 2021, effective
6/30/2021
44
CR 24, December 25, 2021, effective
1/14/2022
45
CR 11, June 10, 2022, effective
6/30/2022
45
CR 17, September 10, 2022, effective
9/10/2022
45
CR 17, September 10, 2022, effective
9/30/2022
45
CR 23, December 10, 2022, effective
1/30/2023