Code of Maine Rules › 06 - DEPARTMENT OF ENVIRONMENTAL PROTECTION › 096 - DEPARTMENT OF ENVIRONMENTAL PROTECTION - GENERAL › Chapter 500 - STORMWATER MANAGEMENT › Appendix 096-500-B - Inspection and maintenance

Current through 2024-29, July 17, 2024
This appendix applies to all projects, except that a project
				  that is eligible for stormwater PBR need only meet the standards in Section 1.
See Appendix D(5) for additional maintenance requirements
				  related to infiltration of stormwater.
1. During construction.
The following standards
				  must be met during construction.
(a) Inspection and corrective action. Inspect disturbed and
				  impervious areas, erosion control measures, materials storage areas that are
				  exposed to precipitation, and locations where vehicles enter or exit the site.
				  Inspect these areas at least once a week as well as before and within 24 hours
				  after a storm event (rainfall), and prior to completing permanent stabilization
				  measures. A person with knowledge of erosion and stormwater control, including
				  the standards and conditions in the permit, shall conduct the
				  inspections.
(b) Maintenance. If best management practices (BMPs) need to
				  be repaired, the repair work should be initiated upon discovery of the problem
				  but no later than the end of the next workday. If additional BMPs or
				  significant repair of BMPs are necessary, implementation must be completed
				  within 7 calendar days and prior to any storm event (rainfall). All measures
				  must be maintained in effective operating condition until areas are permanently
				  stabilized.
(c) Documentation. Keepa log (report) summarizing the
				  inspections and any corrective action taken. The log must include the name(s)
				  and qualifications of the person making the inspections, the date(s) of the
				  inspections, and major observations about the operation and maintenance of
				  erosion and sedimentation controls, materials storage areas, and vehicles
				  access points to the parcel. Major observations must include BMPs that need
				  maintenance, BMPs that failed to operate as designed or proved inadequate for a
				  particular location, and location(s) where additional BMPs are needed. For each
				  BMP requiring maintenance, BMP needing replacement, and location needing
				  additional BMPs, note in the log the corrective action taken and when it was
				  taken.
The log must be made accessible to Department staff and a
				  copy must be provided upon request. The permittee shall retain a copy of the
				  log for a period of at least three years from the completion of permanent
				  stabilization.
2. Post-construction.
The following standards
				  must be met after construction.
(a) Plan. Carry out an approved inspection and maintenance
				  plan that is consistent with the minimum requirements of this section. The plan
				  must address inspection and maintenance of the project's permanent erosion
				  control measures and stormwater management system. This plan may be combined
				  with the plan listed in Section
				  2(a) of this
				  appendix. See Section
				  7(C)(2) for
				  submission requirements.
(b) Inspection and maintenance. All measures must be
				  maintained in effective operating condition. A person with knowledge of erosion
				  and stormwater control, including the standards and conditions in the permit,
				  shall conduct the inspections. The following areas, facilities, and measures
				  must be inspected and identified deficiencies must be corrected. Areas,
				  facilities, and measures other than those listed below may also require
				  inspection on a specific site. Inspection or maintenance tasks other than those
				  discussed below must be included in the maintenance plan developed for a
				  specific site.
NOTE
: Expanded and more-detailed descriptions
				  for specific maintenance tasks may be found in the Maine DEP's
"
Stormwater Management for Maine: Best Management Practices."
(i) Inspect vegetated areas, particularly slopes and
				  embankments, early in the growing season or after heavy rains to identify
				  active or potential erosion problems. Replant bare areas or areas with sparse
				  growth. Where rill erosion is evident, armor the area with an appropriate
				  lining or divert the erosive flows to on-site areas able to withstand the
				  concentrated flows. See permanent stabilization standards in Appendix
				  A(5).
(ii) Inspect ditches, swales and other open stormwater
				  channels in the spring, in late fall, and after heavy rains to remove any
				  obstructions to flow, remove accumulated sediments and debris, to control
				  vegetated growth that could obstruct flow, and to repair any erosion of the
				  ditch lining. Vegetated ditches must be mowed at least annually or otherwise
				  maintained to control the growth of woody vegetation and maintain flow
				  capacity. Any woody vegetation growing through riprap linings must also be
				  removed. Repair any slumping side slopes as soon as practicable. If the ditch
				  has a riprap lining, replace riprap on areas where any underlying filter fabric
				  or underdrain gravel is showing through the stone or where stones have
				  dislodged. The channel must receive adequate routine maintenance to maintain
				  capacity and prevent or correct any erosion of the channel's bottom or
				  sideslopes.
(iii) Inspect culverts in the spring, in late fall, and after
				  heavy rains to remove any obstructions to flow; remove accumulated sediments
				  and debris at the inlet, at the outlet, and within the conduit; and to repair
				  any erosion damage at the culvert's inlet and outlet.
(iv) Inspect and clean out catch basins. Clean-out must
				  include the removal and legal disposal of any accumulated sediments and debris
				  at the bottom of the basin, at any inlet grates, at any inflow channels to the
				  basin, and at any pipes between basins. If the basin outlet is designed to trap
				  floatable materials, then remove the floating debris and any floating oils
				  (using oil-absorptive pads).
(v) Inspect resource and treatment buffers once a year for
				  evidence of erosion, concentrating flow, and encroachment by development. If
				  flows are concentrating within a buffer, site grading, level spreaders, or
				  ditch turn-outs must be used to ensure a more even distribution of flow into a
				  buffer. Check down slope of all spreaders and turn-outs for erosion. If erosion
				  is present, adjust or modify the spreader's or turnout's lip to ensure a better
				  distribution of flow into a buffer. Clean-out any accumulation of sediment
				  within the spreader bays or turn-out pools.
(vi) Inspect at least once per year, each stormwater
				  management pond or basin, including the pond's embankments, outlet structure,
				  and emergency spillway. Remove and dispose of accumulated sediments in the
				  pond. Control woody vegetation on the pond's embankments.
(vii) Inspect at least one per year, each underdrained
				  filter, including the filter embankments, vegetation, underdrain piping, and
				  overflow spillway. Remove and dispose of accumulated sediments in the filter.
				  If needed, rehabilitate any clogged surface linings, and flush underdrain
				  piping.
(viii) Inspect each manufactured system installed on the
				  site, including the system's inlet, treatment chamber(s), and outlet at least
				  once per year, or in accordance with the maintenance guidelines recommended by
				  the manufacturer based on the estimated runoff and pollutant load expected to
				  the system from the project. Remove and dispose of accumulated sediments,
				  debris, and contaminated waters from the system and, if applicable, remove and
				  replace any clogged or spent filter media.
(c) Regular maintenance
(i) Clear accumulations of winter sand in parking lots and
				  along roadways at least once a year, preferably in the spring. Accumulations on
				  pavement may be removed by pavement sweeping. Accumulations of sand along road
				  shoulders may be removed by grading excess sand to the pavement edge and
				  removing it manually or by a front-end loader. Grading of gravel roads, or
				  grading of the gravel shoulders of gravel or paved roads, must be routinely
				  performed to ensure that stormwater drains immediately off the road surface to
				  adjacent buffer areas or stable ditches, and is not impeded by accumulations of
				  graded material on the road shoulder or by excavation of false ditches in the
				  shoulder. If water bars or open-top culverts are used to divert runoff from
				  road surfaces, clean-out any sediments within or at the outlet of these
				  structures to restore their function.
(ii) Manage each buffer's vegetation consistently with the
				  requirements in any deed restrictions for the buffer. Wooded buffers must
				  remain fully wooded and have no disturbance to the duff layer. Vegetation in
				  non-wooded buffers may not be cut more than three times per year, and may not
				  be cut shorter than six inches.
NOTE
: Contact the Department's Division of
				  Watershed Management (Maine DEP) for assistance developing inspection and
				  maintenance requirements for other drainage control and runoff treatment
				  measures installed on the site. The maintenance needs for most measures may be
				  found in the Maine DEP's
"
Stormwater Management for Maine:
				  Best Management Practices."
(d) Documentation. Keepa log (report) summarizing
				  inspections, maintenance, and any corrective actions taken. The log must
				  include the date on which each inspection or maintenance task was performed, a
				  description of the inspection findings or maintenance completed, and the name
				  of the inspector or maintenance personnel performing the task. If a maintenance
				  task requires the clean-out of any sediments or debris, indicate where the
				  sediment and debris was disposed after removal. The log must be made accessible
				  to Department staff and a copy provided to the Department upon request. The
				  permittee shall retain a copy of the log for a period of at least five years
				  from the completion of permanent stabilization.
3. Re-certification.
Submit a certification of
				  the following to the Department within three months of the expiration of each
				  five-year interval from the date of issuance of the permit.
(a) Identification and repair of erosion problems. All areas
				  of the project site have been inspected for areas of erosion, and appropriate
				  steps have been taken to permanently stabilize these areas.
(b) Inspection and repair of stormwater control system. All
				  aspects of the stormwater control system have been inspected for damage, wear,
				  and malfunction, and appropriate steps have been taken to repair or replace the
				  system, or portions of the system.
(c) Maintenance. The erosion and stormwater maintenance plan
				  for the site is being implemented as written, or modifications to the plan have
				  been submitted to and approved by the Department, and the maintenance log is
				  being maintained.
Municipalities with separate storm sewer systems regulated
				  under the Maine Pollutant Discharge Elimination System (MPDES) Program may
				  report on all regulated systems under their control as part of their required
				  annual reporting in lieu of separate certification of each system.
				  Municipalities not regulated by the MPDES Program, but that are responsible for
				  maintenance of permitted stormwater systems, may report on multiple stormwater
				  systems in one report.
4. Duration of maintenance.
Perform maintenance
				  as described and required in the permit unless and until the system is formally
				  accepted by the municipality or quasi-municipal district, or is placed under
				  the jurisdiction of a legally created association that will be responsible for
				  the maintenance of the system. If a municipality or quasi-municipal district
				  chooses to accept a stormwater management system, or a component of a
				  stormwater system, it must provide a letter to the Department stating that it
				  assumes responsibility for the system. The letter must specify the components
				  of the system for which the municipality or district will assume
				  responsibility, and that the municipality or district agrees to maintain those
				  components of the system in compliance with Department standards. Upon such
				  assumption of responsibility, and approval by the Department, the municipality,
				  quasi-municipal district, or association becomes a co-permittee for this
				  purpose only and must comply with all terms and conditions of the
				  permit.
5. Additional requirements.
Additional
				  requirements may be applied on a site-specific basis.