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§ 11.05.060.030 EROSION AND SEDIMENT CONTROL PLAN (ESCP).
   (A)   A professional with a good working knowledge of hydrology and ESCP practices, must prepare the ESCP. A copy of the ESCP must be located on the construction site or within reasonable access to the site. As site construction progresses, the ESC plan may require modification to reflect changes in site conditions.
   (B)   In general, the ESCP will consist of a narrative and a drawing. The project designer may choose to have the narrative included on a drawing or issued as a report. The Montana Department of Transportation is a good source for erosion control details (the Montana Department of Transportation Erosion and Sediment Control Best Management Practices Manual). The ESCP must contain sufficient information to demonstrate to the PWD that potential problems associated with erosion, sediment and pollution have been adequately addressed for the proposed project. The drawings and notes should be clear and concise and describe when and where each BMP is to be implemented and details as necessary.
(Prior Code, § 11.05.060.030) (Ord. 2019-9, passed 9-3-2019; Ord. 2021-15, passed 12-20-2021)
§ 11.05.060.040 BEST MANAGEMENT PRACTICES FOR AN ESCP.
   At a minimum, the following items shall be addressed in the ESCP.
   (A)   Construction sequence.
      (1)   Install temporary BMPs; constructing sediment trapping BMPs as one of the first steps prior to grading;
      (2)   Stabilize roadway approaches and temporary access points with the appropriate construction entry BMP;
      (3)   Protect all permanent stormwater facilities utilizing the appropriate BMPs;
      (4)   Install permanent ESC controls, when applicable; and
      (5)   Remove temporary ESC controls when:
         (a)   Permanent ESC controls, when applicable, have been completely installed;
         (b)   All land-disturbing activities that have the potential to cause erosion or sedimentation problems have ceased; and
         (c)   Vegetation had been established in the areas noted as requiring vegetation on the accepted ESC plan on file with the City PWD.
   (B)   Construction access route.
      (1)   Limit access for construction vehicles to one route whenever possible;
      (2)   Stabilize the construction access routes to minimize the tracking of sediment onto roadways;
      (3)   Install temporary vehicle tracking approach at site entrance locations;
      (4)   Inspect all roadways, at the end of each day, adjacent to the construction access route. If it is evident that sediment has been tracked off-site and/or beyond the roadway approach, removal and cleaning is required;
      (5)   If sediment removal is necessary prior to street washing, it shall be removed by shoveling or sweeping and transported to a controlled sediment disposal area; and
      (6)   If street washing is required to clean sediment tracked off-site, once sediment has been removed, street wash wastewater shall be controlled by pumping back on-site or otherwise prevented from discharging into systems tributary to waters of the state; and, locate wheel washes or tire baths, if applicable to ESCP, on site. Dispose of wastewater into a separate temporary on-site treatment facility in a location other than where a permanent stormwater facility is proposed.
   (C)   Protection of inlets.
      (1)   Protect inlets, drywells, catch basins and other stormwater management facilities from sediment, whether or not facilities are operable, so that stormwater run-off does not enter the conveyance system (both on- and off-site) without being treated or filtered to remove sediment; and
      (2)   Keep roads adjacent to inlets clean; sediment and street wash water shall not be allowed to enter the conveyance system (both on- and off-site) without prior treatment.
   (D)   Run-off from construction sites.
      (1)   Protect down-gradient properties, waterways and stormwater facilities from possible impacts due to increased flow rates, volumes and velocities of stormwater run-off from the project site that may temporarily occur during construction;
      (2)   Run-off from the construction site through the detention/retention storage pond or swales shall be addressed in the construction sequence. No sediment laden water shall pass through the flow control system and discharge to an off-site storm conveyance system;
      (3)   Construct stormwater control facilities (detention/retention storage pond or swales) before grading begins. These facilities shall be operational before the construction of impervious site improvements; and
      (4)   Protect permanent infiltration facilities that are used for flow control during construction.
   (E)   Washout site for concrete trucks and equipment. Designate the location of a slurry pit where concrete trucks and equipment can be washed out. Slurry pits are not to be located in or upstream of a swale, drainage area, stormwater facility or water body, or in an area where a stormwater facility is existing or proposed.
   (F)   Material storage/stockpile.
      (1)   Identify locations for storage/stockpile areas, within the proposed ESCP boundaries, for any soil, earthen and landscape material that is used or will be used on-site;
      (2)   Stockpile materials (such as, topsoil) on-site, keeping off roadway and sidewalks; and
      (3)   Maintain on-site, as feasible, items such as gravel and a roll of plastic, for emergency soil stabilization during a heavy rain event, or for emergency berm construction.
   (G)   Permanent BMPs.
      (1)   Include permanent BMPs, if necessary, in the ESCP to ensure the successful transition from temporary BMPs to permanent BMPs; and
      (2)   Restore and rehabilitate temporary BMPs that are proposed to remain in place after construction as permanent BMPs.
   (H)   Maintenance of BMPs.
      (1)   Inspect on a regular basis (at a minimum, bi-weekly and daily during/after a run-off producing storm event) and maintain all ESC BMPs to ensure successful performance of the BMPs. Conduct maintenance and repair in accordance with individual ESC BMPs outlined in this section; and
      (2)   Remove temporary ESC BMPs within 30 days after they are no longer needed. Permanently stabilize areas that are disturbed during the removal process.
(Prior Code, § 11.05.060.040) (Ord. 2019-9, passed 9-3-2019; Ord. 2021-15, passed 12-20-2021)
§ 11.05.060.050 STORMWATER POLLUTION PREVENTION PLAN.
   Construction sites or activities disturbing one acre or more, or when stormwater discharge to state waters can occur, the MDEQ requirements for the general permit for stormwater discharges associated with construction activity apply. Requirement associated with the general permit and SWPPP can be found on DEQ’s website.
(Prior Code, § 11.05.060.050) (Ord. 2019-9, passed 9-3-2019; Ord. 2021-15, passed 12-20-2021)
MODIFICATION TO MWPSS
§ 11.05.070.010 CONTRACTOR QUALITY CONTROL AND OWNER QUALITY ASSURANCE.
   The minimum quality control testing to be performed by the contractor is identified below.
Test Specification/Material
Test Method
Minimum Required Frequency
Test Specification/Material
Test Method
Minimum Required Frequency
   Asphalt Concrete Pavement
Asphalt concrete pavement (base course and surface course)
Asphalt oil content
1 test/first day or 1/1000 TN
Gradation
1 test/first day or 1/1000 TN
Marshal test
1 test/day or 1/1500 TN
Mix design
1 submittal
Rice specific gravity (MPWSS 02510)
1 test/day or 1/1500 TN
Compaction of asphalt concrete pavement
In-place density/thickness (MPWSS 02510)
1 core/day or 1core/500 TN
   Earthworks
Compaction of crushed base course for roadways
In-place density (MPWSS 02235/1.3) 95% minimum
1 test/lift/4,00 square feet
Compaction of crushed base course under curbs, gutters and sidewalks
In-place density (MPWSS 02235/1.3) 95% minimum
1 test/lift/200 LF (C & G) or
1 test/lift/1,000 square feet (flatwork)
Compaction of subbase course for roadways
In-place density (MPWSS 02234/1.3) 95% minimum
1 test/lift/4,000 square feet
Compaction of subgrade and embarkment for roadways
In-place density (MPWSS 02230/1.3) 95% minimum
1 test/lift/4,000 square feet
Compaction of subgrade under curbs, gutters and sidewalks
In-place density (MPWSS 02230/1.3) 95% minimum
1 test/lift/200 LF (C & G) or 1 test/lift/1,000 square feet (flatwork)
Crushed base course
Gradation - moisture density - fractured faces (crushed) - LA abrasion, LL, PL and PI (MPWSS 02235)
1 submittal
Pipe bedding
Type I bedding gradation and plasticity index/type II bedding gradation (MPWSS 02221)
1 submittal
Subbase course
Gradation - moisture density - fractured faces (crushed) - LA abrasion, LL, PL and PI (MPWSS 02234)
1 sbmittal
Subgrade and embankment
Moisture-density (MPWSS 02230)
1 submittal per soil type encountered/1 submittal per borrow source
Trench backfill
Moisture-density (MPWSS 02221)
1 sub/soil type encountered
1 submittal/borrow source
Trench compaction
In-place density (MPWSS 02221/1.4) 97% minimum
1 test/lift/200 LF
Trench compaction (laterals outside the road template, structures, valves, hydrants and manholes)
In-place density (MPWSS 02221/1.4) 97% minimum
1 test/for each 2 feet of vertical depth/2 feet from edge of structure, valve, hydrant or manhole
   Portland Cement Concrete
Portland cement concrete
Mix design
1 submittal
Portland cement concrete flatwork and curb and gutter
Air, slump, and 7-day and 28-day compression strength (MPWSS 025152)
Every 50 CY
Portland cement concrete pavement
Air, slump, and 7-day and 28-day compression strength (MPWSS 025152)
Every 100 CY
 
(Prior Code, § 11.05.070.010) (Ord. 2019-9, passed 9-3-2019; Ord. 2021-15, passed 12-20-2021)
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