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The Delaware River Basin Commission (DRBC) at its December 4, 2013 business
meeting adopted updated water quality criteria for polychlorinated biphenyls
(PCBs) in the Delaware Estuary and Bay and also for pH in interstate tidal and
non-tidal reaches of the main stem Delaware River.
The updated PCB criteria for the protection of human health
from carcinogenic effects is 16 picograms/liter. This number, based upon the
most current methodology and scientific data available, is now a uniform value
for the entire Delaware Estuary and Bay (DRBC Water Quality Zones 2-6). The
criteria previously varied according to the water quality zone, differed from
that of the basin states, and did not take into account site-specific data and
current U.S. Environmental Protection Agency (U.S. EPA) guidance on the
development of human health criteria.
This update was originally proposed in 2009, but action was
deferred pending further refinement of an implementation strategy to support
achievement of the revised PCB water quality criteria. While comment on an
updated implementation strategy was solicited simultaneously with the current
PCB criteria revision, there was no planned commission action on the strategy.
The Delaware Estuary and Bay are considered impaired for
PCBs, and the U.S. EPA has established total maximum daily loads (Stage I TMDLs)
for these waterbodies. A TMDL expresses the maximum amount of a pollutant that
a waterway can receive and still attain water quality standards. With DRBC’s
adoption of revised PCB criteria, it is anticipated that the U.S. EPA will
establish new TMDLs (Stage 2 TMDLs) corresponding to the updated criteria. In
the associated report announcing the Stage 2 TMDLs, the U.S. EPA will include
the proposed implementation strategy as an appendix and will solicit comment on
the report and strategy in 2014.
PCBs have been classified by the U.S. EPA as a probable human
carcinogen. The U.S. banned the manufacture and general use of PCBs in the late
1970s, but not before 1.5 billion pounds of the substance was
produced.
The updated PCB criteria was developed under the guidance of
the commission’s Toxics Advisory Committee, comprised of representatives of the
four basin states – Delaware, New Jersey, New York, and Pennsylvania – and
members of the academic, agricultural, public health, industrial and municipal
sectors, and non-governmental environmental community. The rulemaking was
noticed in the federal and state registers, with the full text of the proposed
rule changes and related materials posted on the DRBC web site on August 1,
2013. A public hearing was held on September 10, with written comments accepted
through September 20.
The commissioners at the December 4 meeting, which was held
at the Washington Crossing Historic Park Visitor Center, also adopted revised pH
water quality criteria for the main stem Delaware River and tidal tributaries up
to the head of tide. DRBC’s pH criteria have not been updated since being
established in 1967. The old pH criteria were expressed as ranges and were
different for the tidal (between 6.5 and 8.5) and non-tidal (between 6 and 8.5)
river. The approved criteria range (between 6.5 and 8.5) is now uniform for the
entire main stem Delaware (except towards natural conditions in certain sections
of the river), minimizes regulatory inconsistencies between DRBC criteria and
that of the basin states and the U.S. EPA, and better addresses natural pH
cycles in the main stem Delaware River.
The revisions to the pH criteria were unanimously endorsed by
the DRBC’s Water Quality Advisory Committee, comprised of regulators, municipal
and industrial dischargers, academicians, and environmental organizations, which
advises the commissioners on technical matters relating to water quality within
the basin. The rulemaking was noticed in the federal and state registers, with
the full text of the proposed rule changes and related materials posted on the
DRBC web site on September 20, 2013. A public hearing was held on October 24,
with written comments accepted through November 21.
Additional information is available on the commission’s web
site at www.drbc.net.
The DRBC was formed by compact in 1961 through legislation
signed into law by President John F. Kennedy and the governors of the four basin
states with land draining to the Delaware River. The passage of this compact
marked the first time in our nation’s history that the federal government and a
group of states joined together as equal partners in a river basin planning,
development, and regulatory agency.
