Chapter 4 Generally Applicable Development Standards
Appendix 4H Erosion Prevention and Sediment Control Page4 of 5
SECTION 159.03 REVIEW STANDARDS & CRITERIA
- EPSC standards general
MSD shall review all EPSC
plans for compliance with the following general standards and review criteria:
- Overall Design Goal. A design removal efficiency g9al of 80% for
total suspended solids from land disturbing activities shall be applied to the
design, review, and approval of EPSC plans. The following structural and
non-structural standards are to be utilized to achieve this goal.
- Compliance with MSD Design Manual. Standard Specifications
and Standard Drawings. Except where innovative or alternative management
practices are approved pursuant to Section 159.03.A.2. below, all EPSC measures
shall be designed and installed in accordance with the specifications contained
in the MSD Design Manual, Standard Specifications and Standard Drawings, as it
may be revised from time to time, which is hereby incorporated by reference
into this Ordinance.
- Non-structural Site Management Practices. Non-structural
site management practices to prevent erosion and minimize sediment discharge
shall be considered in MSDs evaluation of Section 159.03.A.1. above. Such
practices may include the following standards:
- Minimize site disturbance to preserve and maintain
existing vegetative cover;
- Limit the number of temporary access points to the site
for land disturbing activities;
- Phase and sequence construction activities;
- Locate temporary and permanent soil disposal areas, haul
roads and construction staging areas to minimize erosion, sediment transport
and disturbance to existing vegetation.
Where attainment of this design removal efficiency
goal through the use of structural and non-structural measures is not
practicable, the permittee shall submit written justification to MSD for review
and approval.
- Alternative Management Practices. To encourage the development
and testing of alternative EPSC measures, alternative management practices that
are not included in the MSD Design Manual, Standard Specifications and Standard
Drawings may be allowed upon review and approval of MSD.
- A Permittee seeking to use an alternative management
practice shall concurrently submit substantial evidence that the proposed
measure will perform at least equivalent to a currently approved control
contained in the MSD Design Manual, Standard Specifications and Standard
Drawings. Evidence may include, but is not limited to, peer-review by a panel
of registered professional engineers and research results as reported in
professional journals or other literature.
- If MSD finds the control or practice has failed or is
inadequate to contain sediment onsite, the Permittee shall remove and replace
it with a control approved by MSD and found in the MSD Design Manual, Standard
Specifications and Standard Drawings.
- EPSC standards specific
MSD shall review all EPSC
plans for compliance with the following specific standards and review criteria:
- Sediment Tracking Control. Stabilized construction entrances
shall be located and utilized at all points of ingress/egress on a construction
site. The transfer of soil, mud and dust onto public rights-of-ways shall be
minimized.
- Construction Dewaterinq Operations. Whenever construction
dewatering operations are required on a site, they shall be conducted according
to the specifications set forth in the MSD Design Manual, Standard
Specifications and Standard Drawings.
- Crossings of waterways during construction shall be minimized
and approved by MSD. Encroachment into stream buffers, riparian areas and
wetlands shall be avoided.
- Topsoil shall be stockpiled and preserved from erosion or
dispersal both during and after site grading operations.
- Temporary Stabilization Measures. Where construction or land
disturbance activity will or has temporarily ceased on any portion of a site,
temporary site stabilization measures shall be required as soon as practicable,
but no later than 14 calendar days after the activity has ceased. Permanent or
temporary stabilization shall be completed within:
- 14 calendar days for the surface of all perimeter dikes,
ditches, swales, perimeter slopes, and all slopes greater than 3 horizontal to
1 vertical (3:1);
- 14 calendar days as to all other disturbed or graded areas
on the project site.
The requirements of Section 159.03.B.5(a) and
159.03.B.5(b) do not apply to those areas which are shown on the plan and
currently being used for material storage or for those areas on which
construction activities are currently being performed or to prepared structural
subgrades, provided that structural EPSC measures remain in place.
- Final Stabilization. Final Stabilization of the site shall be
required within 14 calendar days of construction completion.
- Temporary Structural Controls installed during construction
shall be designed to accomplish maximum stabilization and control of erosion
and sedimentation, and shall be installed, maintained, and removed according to
the specifications set forth in the MSD Design Manual, Standard Specifications
and Standard Drawings. All temporary structural controls shall function as
designed when controlling the peak runoff resulting from the storm event
identified in the MSD Design Manual, Standard Specifications and Standard
Drawings.
- All Permanent Structural Controls, including drainage facilities
such as channels, storm sewer inlets, and detention basins, shall be designed
according to the standards set forth in the MSD Design Manual, Standard
Specifications and Standard Drawings.
SECTION 159.04 MAINTENANCE & PERFORMANCE
REQUIREMENTS
- Maintenance and damage remediation
- Maintenance During Construction:
- The Permittee, or his/her designee, shall be required to
conduct continuing inspections of all EPSC measures, and direct the appropriate
persons to make any repairs or modifications necessary, within 48 hours of the
initial discovery of a control failure or violation, unless extenuating
circumstances such as weather or complexity of repairs or modifications justify
a longer time frame. At a minimum, such inspections shall occur every seven (7)
calendar days and within 24 hours after each storm event that produces 0.5
inches or more of precipitation.
- In addition, silt accumulation upstream of temporary
controls shall be removed when the control reaches the percentage of storage
capacity established for the maintenance of that particular type of control in
the MSD Design Manual, Standard Specifications and Standard Drawings.
- A copy of the EPSC plan and records of all inspections,
repairs, and modifications shall be available on-site throughout the duration
of the construction or land-disturbing activity. All records of inspection
shall be in a form specified by MSD and shall include the date and time of
inspection, and the name and signature of the inspector as defined in Section
159.04 A.I.(a) above. These records shall be made available to agency
inspectors upon request.
- If the Permittee chooses to use a CCR for site inspections
and monitoring of all land disturbing activities, the Permittee shall sign a
statement giving the CCR full authority to inspect the site and to require
necessary measures to maintain compliance. The name, address, and phone number
of the CCR shall be noted on the cover sheet of the submitted detailed EPSC
plan, but in no instance later than the time notice of construction is filed
with MSD. If requested, the CCR shall submit signed and dated weekly inspection
logs to the appropriate inspection agency. Copies of such logs shall be
maintained on site and shall be signed and dated by the CCR.
- Post-Construction Maintenance. Following release or acceptance
of a project (and termination of the site disturbance permit), the property
owner shall be responsible for maintaining the project site in a manner to
prevent soil erosion and sedimentation in violation of this Ordinance.
- Damage Remediation. In the event of adverse impacts or off-site
degradation resulting from improper controls or practice in violation of this
Ordinance, MSD shall have the authority to take the following action:
- Determine the extent of damage resulting from noncompliance
with the plan or failure to maintain the practices required by the plan;
- Determine the impact and severity of the resulting adverse
impacts or off-site degradation;
- Require and approve an agreement with the Permittee for
correction and clean- up of the existing damage and an agreement for prevention
of future damage.
- Cost incurred by MSD and other agencies, as a result of
having to hire outside expertise, to determine the extent, impact and severity
of damage and in remediating any such damage shall be collected from the
Permittee.
Failure of the Permittee to implement the agreement
according to its terms shall constitute a violation of this Ordinance, and
subject the Permittee to all applicable enforcement actions and penalties.
- Performance assurances
- The Permittee shal| be responsible for the installation, good
repair, maintenance, proper functioning and ultimate removal of all temporary
and permanent EPSC measures.
- Fiscal Surety Required. For all land disturbing activities
subject to a Type I or Type II review under this Ordinance, the Permittee may
be required to post a fiscal surety, consisting of a performance bond or other
instrument, acceptable to and approved by MSD. When a fiscal surety is
required, the following conditions will apply.
- Timing of Surety. The surety shall be posted no later than
the issuance of a site disturbance permit or, with MSD approval, prior to
issuance of a certificate of occupancy, as applicable.
- Combination with Other Appropriate Bonds. Whenever feasible,
the fiscal surety for EPSC required by this section may be combined with and
posted as Part of the sanitary sewer lateral extension bond or subdivision
performance bond required for all subdivisions approved pursuant to the
Development Code.
- Amount of Surety. For activities subject to Type I review,
the amount of the surety for EPSC shall be the cost of the approved EPSC
measures to be installed on the site and any prescribed site revegetation or
restoration measures, including labor costs. MSD shall have the discretion to
set alternate amounts for or to waive a surety for activities subject to Type
II review that are commensurate with the complexity or size of the project. The
final amount of the surety shall be determined by MSD and shall be in addition
to any other surety required as Part of subdivision or development
approval.
- Use of Surety. If at any time following the period allowed
to the Permittee to complete his/her obligations under this Ordinance, MSD
finds that:
- The required temporary or permanent improvements or
control measures have not been installed or maintained properly,
- The required temporary or permanent improvements are not
in good repair or functioning properly, or
- Required revegetation and restoration of a site have not
been completed as required, then
In addition to other enforcement remedies, MSD may
declare the Permittee to be in default if it does not appear that the
improvements or controls will be completed or repaired within a reasonable time
considering the potential for harm, inconvenience, nuisance or annoyance to
others including nearby property owners.
Upon declaration of default,
MSD shall demand such amounts from the surety as required to remedy the
default. In the event that amounts available from the surety are sufficient to
cover the costs of remedying the default, such surety shall be collected and
used in full in such proportion as the MSD determines to be just and equitable
based upon apparent responsibility for the default. Anyone claiming to be
aggrieved by such determination shall have as his/her exclusive remedy a cause
of action for contribution or indemnity against the parties responsible for the
default. The determination of MSD shall not be used as evidence in support of
or against responsibility in such cause of action, and MSD shall not be made a
party to such action.
- Release of Surety. Application for release of a fiscal
surety required by this Ordinance may be made by filing a certificate with MSD
bearing a notice that false statements made therein are punishable. MSD may
make an inspection of the property and shall grant a release of the surety upon
determining that:
- Site construction is finished,
- Final stabilization has been completed,
- The site disturbance permit has been terminated,
- The required improvements and controls are properly
installed, are in good repair, and are functioning properly,
- Temporary controls have been removed, and
- There is no reason to believe that construction on the
lot has or will cause the malfunctioning of installed improvements on other
property.
Imposition of Lien. In addition to or as an alternative
to use of any fiscal surety, MSD shall have the option of placing a lien on any
property on which the Permittee has failed to properly install, keep in good
repair, or maintain the proper functioning of all required temporary and
permanent EPSC measures or has failed to complete required revegetation or
restoration measures. The amount of the lien may cover necessary costs of
ensuring compliance with applicable provisions of this ordinance, including but
not limited to any necessary remedial and restoration measures to alleviate the
adverse impacts or off-site degradation, and all associated administrative
costs.