Current through Register Vol. 24-06, March 15, 2024
(1) Approved manual required. Six months
after the effective date of ecology's stormwater management manual or six
months after the effective date of this chapter, whichever is later, WSDOT
shall submit to ecology a highway runoff manual. If WSDOT proposes to adopt a
manual other than ecology's stormwater management manual as its highway runoff
manual, WSDOT shall formally consult with the tribes and local governments
about the contents of the highway runoff manual. The highway runoff manual
shall be consistent with ecology's stormwater management manual and shall be
adopted by WSDOT only after obtaining ecology's approval. After obtaining
ecology's approval, WSDOT shall use the highway runoff manual to direct
stormwater management for its existing and new facilities and rights of way in
the Puget Sound basin.
(2)
Amendments to manual.
(a) Ecology initiates
amendments. If ecology amends its stormwater management manual to change or add
a BMP or other technical requirement that applies to highways, ecology shall
notify WSDOT in writing and send WSDOT a copy of the amendment. This
notification shall include ecology's determination as to whether the highway
runoff manual complies with the amendment. If the highway runoff manual does
not comply with the amendment, WSDOT shall submit proposed amendments within
sixty days unless ecology agrees to a time extension. Such proposed amendment
shall be subject to ecology's review and approval.
(b) WSDOT initiates amendments. Amendments
proposed by WSDOT to the approved highway runoff manual shall be submitted to
ecology for review and approval. WSDOT shall formally consult with affected
tribes and local governments during the development of proposed amendments.
Ecology shall review and approve, conditionally approve or deny the proposed
amendments within sixty days from the submittal date.
(3) More stringent standards.
(a) WSDOT shall use the minimum standards
established in the highway runoff manual but may use more stringent
standards.
(b) When a state highway
is located in the jurisdiction of a local government that is required by
ecology to utilize more stringent standards to protect the quality of receiving
waters, WSDOT shall comply with the same standards to promote uniform
stormwater treatment.
(c) WSDOT
shall comply with standards identified in watershed action plans for WSDOT
rights of ways as required by WAC 400-12-570.
(4) Project coordination. WSDOT shall consult
with appropriate tribes and local governments and evaluate local conditions for
design, construction, and maintenance of stormwater facilities as indicated in
WSDOT's utilities manual. Other agencies and organizations that have an
interest or expertise in stormwater may also be consulted. WSDOT, tribes, and
local governments are encouraged to jointly develop and maintain stormwater
facilities.
(5) Contents of manual.
The highway runoff manual shall include, but not be limited to, the following:
(a) BMPs for the control of erosion and
sedimentation from construction sites, including standards for operation and
maintenance;
(b) Hydrologic
analysis procedures, including selection of design storms and estimation of
runoff;
(c) Design, operation, and
maintenance standards for retention and/or detention facilities and conveyance
systems that shall emphasize systems which maximize water quality benefits as
well as water quantity control, such as inclusion of biofiltration techniques
where practicable;
(d) BMPs for the
control of pests, excluding weed control which shall be addressed in the
vegetation management program described in WAC
173-270-040;
(e) BMPs for the selection and use of deicing
chemicals and traction grit which, as a minimum, shall consist of the
following: (i) Traction grit particles should be as large as suitable for
application on highways for traction purposes because large particles are less
readily transported into waters of the state; (ii) selection and use of deicing
chemicals shall include consideration of potential effects on water quality and
the beneficial uses of potentially affected waters; (iii) stockpiles containing
deicing chemicals shall be investigated for existing and potential water
quality problems; and (iv) stockpiles that have an identified problem shall be
covered, curbed, diked, placed on an impervious surface, and/or located so
runoff can not carry dissolved chemicals into waters of the state;
and
(f) BMPs for waste disposal
from highway runoff system maintenance.
(6) Experimental BMPs.
(a) WSDOT request. WSDOT may request in
writing that ecology approve the use of an experimental BMP for one or several
sites. The request shall include, but need not be limited to, a description of:
(i) The experimental BMP; (ii) why the experimental BMP is being requested;
(iii) why the BMPs in the highway runoff manual are not appropriate; (iv)
applicable construction techniques; (v) the site or sites at which use of the
experimental BMP is proposed; (vi) the characteristics of the site or sites;
(vii) design criteria for the experimental BMP; (viii) maintenance procedures;
(ix) cost estimates; (x) monitoring procedures; (xi) the time needed for
monitoring; (xii) the anticipated results; (xiii) if appropriate, an approved
BMP that could be used if the experimental BMP fails; and (xiv) consultation
with interested and affected parties including tribes, local governments, and
contiguous property owners.
(b)
Ecology review and approval. After reviewing WSDOT's request, ecology may
approve, conditionally approve, or deny the use of the experimental BMP for
specific sites. Any approval shall be for a period of time not to exceed four
years unless ecology determines, upon request and justification by WSDOT, that
unusual circumstances justify a longer time period.
(c) Evaluation criteria. In evaluating an
experimental BMP, ecology shall consider factors it deems appropriate,
including, but not limited to: The experimental BMP's effectiveness in
protecting water quality and beneficial uses; its reliability, cost, ease of
construction; and maintenance requirements.
(d) BMP status. Before ecology's
authorization for WSDOT's use of the experimental BMP expires, WSDOT shall
consult with affected tribes, local governments, or property owners. WSDOT
shall document the results of the experimental BMP and shall determine whether
to request amendment of the highway runoff manual to include the experimental
BMP as an approved BMP. Before ecology's authorization expires, WSDOT shall
either request an amendment to the highway runoff manual under subsection
(2)(b) of this section or inform ecology in writing that it is not proposing to
amend the highway runoff manual to include the BMP. Based upon the predicted
results in the original request, monitoring data and other information relevant
to WSDOT's request, ecology shall determine whether an experimental BMP that is
not proposed to be included in the highway runoff manual shall be replaced with
an approved BMP.
Statutory Authority:
Chapters
90.48 and 90.70 RCW.
91-11-091 (Order 91-06), § 173-270-030, filed 5/21/91, effective
6/21/91.