Eastern Washington Phase II Municipal Stormwater Permit Overview – 2024 to 2029
The timeline below provides an overview of major program deadlines for implementing Permit requirements of S5 Stormwater Management Program
(SWMP) and S8 Monitoring and Assessment for Continuing City, Town, and County Permittees (By Date means “no later than…”). This is guidance only.
Table paraphrases requirements and does not include all ongoing program elements. Please see the Permit for additional details and related
requirements.
S5 Permit
Components
Ongoing
Program
Implementation
2024
2025
2026
2027
2028
2029
A. Stormwater
Management
Plan
Annually update
& submit the
SWMP with
Annual Report
(S9)
-A.3.a.i activity
tracking: track #
of inspections,
follow up
actions, official
enforcement,
public ed
activities
-A.3.a.ii cost
tracking: track
the cost (or
estimate) of
development and
implementation
of each
component of
the SWMP
By March 31
(ongoing from
this year
forward):
Submit the
(estimated) cost
of development
and
implementation
of each
component of
the SWMP and
sources of
funding.
S5 Permit
Components
Ongoing
Program
Implementation
2024
2025
2026
2027
2028
2029
A.5
Coordination
Ongoing
coordination
By March 31:
Submit
description of
internal
coordination
mechanisms
among
departments.
B.1 Public
Education &
Outreach
Ongoing:
Implementation
of ed & outreach
programs and
stewardship
By Dec 31:
Measure
understanding/
adoption of at
least one priority
audience in at
least one
subject area and
document how
this evaluation
process will
direct
implementation
of the ongoing
E&O program.
By Jan 1: Begin
to provide,
partner, or
promote
stewardship
opportunities.
S5 Permit
Components
Ongoing
Program
Implementation
2024
2025
2026
2027
2028
2029
B.2 Public
Involvement &
Participation
Ongoing:-
Document
opportunities for
public, including
overburdened
communities,
and specifically,
highly impacted
communities, to
participate in
development of
the SWMP.
-Post SWMP and
Annual Report to
website by May
31.
By Dec
31:Document
methods used
to identify
overburdened
communities
S5 Permit
Components
Ongoing
Program
Implementation
2024
2025
2026
2027
2028
2029
B.3 IDDE
Ongoing
– Maintain
mapping data
-Implement
program to
prohibit, address,
and eliminate
illicit discharges.
– Train staff
– Field screen on
average 12% of
the MS4 each
year.
-Track and
maintain records
through WQ
WebIDDE or
submit .xml
following the App
7 schema.
By March
31:Submit
locations of all
known outfalls
according to
standardized
template in the
Annual Report.
By Dec 31:Use
available,
existing data to
map tree
canopy to
support
stormwater
management on
Permittee-
owned or
operated
properties.
– Coordinate
with firefighting
agencies to be
notified when
PFAS-containing
AFFFs are used
during
emergency
firefighting
activities.
By Jan 1:Update
and implement
procedures to
minimize
discharges to
MS4 during
firefighting post-
emergency
cleanup and
disposal
activities.
By July
1:Update
ordinance or
other regulatory
mechanism in
effect, if
necessary, to
meet the
requirements of
this section.
By Dec 31:Map
tributary
conveyances to
all known
outfalls and
discharge points
with a 24''
nominal
diameter or
larger, or an
equivalent
cross-sectional
area for non-
pipe systems.
By Dec 31:Using
available,
existing data,
map
overburdened
communities in
relation to
permanent
stormwater
facilities owned
or operated by
the Permittee,
outfalls,
discharge
points, and tree
canopy on
Permittee-
owned/operated
properties.
S5 Permit
Components
Ongoing
Program
Implementation
2024
2025
2026
2027
2028
2029
B.4
Construction
Site Stormwater
Runoff Control
Ongoing:
– Implement &
enforce program
to reduce
pollutants in
runoff.
– Train Staff
By June 30:
Adopt and make
effective local
program that
meets
requirements of
S5.B.4.a.i-v.
B.5 Post
Construction
Stormwater
Management for
New &
Redevelopment
Ongoing:-
Implement &
enforce program
to address
pollutants in
runoff from post-
construction
projects which
meet the
thresholds of App
– Train Staff
By July 1,
2026:Regional
Manual (serves
two or more
Permittees)
option:
Permittees
submit draft
enforceable
requirements,
technical
standards, and
manuals that
correspond to
updated in
Appendix 1 for
functional
equivalency
review by
Ecology.
By June
30:Adopt and
make effective
local program
that meets
requirements of
S5.B.5.b.i-v.
-Regional
Manual option:
adopt and make
effective local
program.
S5 Permit
Components
Ongoing
Program
Implementation
2024
2025
2026
2027
2028
2029
B.6 Operations &
Maintenance
Ongoing:-
Inspect and
maintain
Permittee
owned/operated
catch basins and
stormwater
BMPs/facilities,
and regulated
stormwater
BMPs/facilities.-
Maintain updated
SWPPP at heavy
equipment,
maintenance,
and storage
facilities.
-Train Staff
Dec 31:
Inspect All
catch basins
and inlets
owned or
operated by
the Permittee,
and every two
years
thereafter.
By June
30:Review and,
as needed,
update the O&M
plan to meet the
requirements of
this section.
July 1:Develop
and implement
street sweeping
program.
Between July –
Dec:Sweep
priority areas
once
By March 31
(ongoing from
this year
forward):Report
on all items
described in
S5.B.6.b.v(a-f)
Between July-
Sept (ongoing
from this year
forward):Sweep
priority areas
once
Annually
(ongoing from
this year
forward):Sweep
priority areas 2
additional times
to the July-Sept
event at timing
determine by
Permittee.
S8 Permit
Components
Ongoing
Program
Implementation
2024
2025
2026
2027
2028
2029
S8.A
Dec 31:
City and County
Permittees shall
adopt and
implement tree
canopy goals
and policies to
support
stormwater
management.
S8.B
Stormwater
Management
Program
(SWMP)
Effectiveness
and Source
Identification
Studies
If applicable,
continue to
participate in
implementation
of Ecology
approved studies
from the 2014-
2024 permit
terms.
Dec 1:Notify
Ecology in
writing,
certified with a
G19 signature,
which S8.B.3
option for
Effectiveness
and Source
Identification
Studies you'll
carry out for
this permit
term.
By Aug
15:Permittees
who selected
S8.B.3.b shall
submit their first
annual payment
in accordance
with S8.D
instructions.
S8 Permit
Components
Ongoing
Program
Implementation
2024
2025
2026
2027
2028
2029
S8.C
Regional SWMP
Effectiveness
Study
(applies only to
Permittees who
choose to
coordinate with
other
Permittees in
their Urban
Area to Plan
and begin an
additional
Stormwater
Management
Program, per
S8.B.3.a)
By June 30:
Submit a brief
description of
the study, with a
list of project
participants and
their role(s) in
the study.
By June 30:
Submit a
detailed study
design proposal
to Ecology.
By Dec 31:
Submit a
completed
QAPP
By June 30:
Begin to
conduct the
study, or within
3 months of
receiving
Ecology's
approval of the
QAPP
(whichever is
later).
S8 Permit
Components
Ongoing
Program
Implementation
2024
2025
2026
2027
2028
2029
S8.E
Stormwater
Discharge
Monitoring
(applies only to
Permittees who
choose to
conduct
stormwater
discharge
monitoring, per
S8.B.3.c, in lieu
of participation
in the
effectiveness
and source
identification
studies.)
By June
30:Submit a
draft stormwater
discharge
monitoring
QAPP for review
and approval.
By August
15:Final QAPP
submitted to
Ecology, or
within 60 days of
receiving
Ecology's
comments on
the draft
(whichever is
later).
By Oct 1:Flow
monitoring shall
begin, or within
30 days of
receiving
Ecology’s final
QAPP approval
(whichever is
later).
By Oct
1:Stormwater
discharge
monitoring fully
implemented.