EPA
United States Environmental Office of Water EPA-822-F-04-001
Protection Agency 4304T December 2003
FACT SHEET
Notice of Draft Revised Ambient Water
Quality Criteria for the Protection of
Human Health: Chloroform and Request
for Scientific Views
EPA is announcing the availability of a draft-Revised Human Health Ambient Water Quality Criteria
(AWQC) for Chloroform, recommending draft criteria for Chloroform and requesting scientific views
from the public. We have revised the criteria according to the procedures and information described
in EPA's Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human
Health (2000 Human Health Methodology). The draft revised criteria reflect the Agency's
consideration of recent advances in scientific information.
Background
Chloroform (trichloromethane) is a colorless, volatile liquid. It is a nonflammable chemical that is
slightly soluble in water. Because chloroform is relatively volatile, it tends to escape from
contaminated water or soil into air. It may also be released in vapor from some types of industrial or
chemical operations. Chloroform appears to be ubiquitous in the environment. It is derived primarily
from various industrial and chemical processes, or as a by-product of disinfecting water with
chlorine.
EPA originally published Human Health AWQC for chloroform in 1980 (45 FR 79318, October
1980). We updated these criteria by incorporating newer toxicity values from EPA's Integrated Risk
Information System (IRIS) data base and published them in the 1992 Proposed National Toxics Rule
(57 FR 60848). The criteria values promulgated in the National Toxics Rule are the same values in
EPA's latest compilation of national recommended water quality criteria (67 FR 79091, December
27, 2002). The chloroform criteria currently recommended by EPA are: 5.7 |ig/L for consumption of
water + organisms and 470 |ig/L for consumption of organisms only.
The EPA recommended AWQC provide guidance to states and authorized tribes in adopting water
quality standards. The criteria provide a scientific basis for EPA to develop Federally promulgated
water quality standards under section 303(c) of the Clean Water Act, should such action be
necessary. Once final, these criteria are guidance for states and tribes and, in themselves, have no
binding legal effect. However, they may form the basis for state water quality standards and become
enforceable through NPDES permits or other environmental programs. These new draft revised
chloroform criteria are published pursuant to Section 304(a) of the Clean Water Act (CWA).
-------
What's new about the draft revised criteria?
The draft revised criteria reflect the Agency's consideration of the recent advances in scientific
information available since the 2002 criteria were recommended. We have revised the criteria by
implementing the 2000 Human Health Methodology. Specifically, we have incorporated:
the national fish consumption rate (17.5 grams per day) recommended in the 2000 Human
Health Methodology;
• the IRIS reference dose (RfD) that was revised in October 2001 (http ://www.epa.gov/iris/):
• new relative source contribution (RSC) analysis and values derived using data from the
Relative Source Contribution document recently developed by the Office of Water in support
of the Stage 2 Disinfectants and Disinfection Byproducts - Proposed Rule (68 FR49548); and
bioaccumulation factors developed according to the procedures described in the 2000 Human
Health Methodology.
What are the Draft Revised National Recommended Water Quality Criteria for Chloroform?
The draft revised criterion is 68 |ig/L for consumption of water and aquatic organisms and 2,400
|ig/L for consumption of aquatic organisms only.
How do I get a copy of the new draft chloroform document?
You can get copies of "Water Quality Criteria for the Protection of Human Health: Chloroform-
Revised Draft" (EPA-822-R-04-002) from EPA's Water Resource Center by calling (202) 566-1729.
You can request a copy by sending an e-mail to center.water-resource@epa.gov or by conventional
mail to: EPA Water Resource Center, 4101T, 1200 Pennsylvania Avenue, N.W., Washington, DC
20460. You can also download the document from EPA's web site at:
http ://www. epa. gov/waterscience/humanhealth/docs/.
------- |