Diese Präsentation wurde erfolgreich gemeldet.
Wir verwenden Ihre LinkedIn Profilangaben und Informationen zu Ihren Aktivitäten, um Anzeigen zu personalisieren und Ihnen relevantere Inhalte anzuzeigen. Sie können Ihre Anzeigeneinstellungen jederzeit ändern.
A Fairfax County, VA, publication
Department of Public Works and Environmental Services
Working for You!
Stormwater Mainte...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Course Schedule
AM session (includes two short breaks)
– History of S...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-General Safety
3
The County’s private inspect...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Ponds (WP, DP)
• Wet Ponds (WP) and Dry Ponds...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Ponds (WP, DP)
WET POND COMPONENTS Profile of...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Ponds (WP, DP)
DRY POND COMPONENTS - Under th...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Ponds (WP, DP)
DRY POND COMPONENTS - Dry Pond...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Ponds (WP, DP)
Routine Deficiencies Observed:...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Ponds (WP, DP)
Water level inconsistent with ...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Ponds (WP, DP)
Trickle Ditches (DP only)
10
T...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Ponds (WP, DP)
Dam/Berm - Erosion and Failure...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Ponds (WP, DP)
Dam/Berm - Cave-Ins and Animal...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Ponds (WP, DP)
Vegetation & Trash/Debris Accu...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Ponds (WP, DP)
Trees and Woody Vegetation on ...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Ponds (WP, DP)
Riser/Trash Rack
15
Significan...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Ponds (WP, DP)
Outfalls
16
Undermining below ...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Ponds (WP, DP)
• Common Remedies
– Algal bloo...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Ponds (WP, DP)
• Common Remedies
– Repair/rep...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Ponds (WP, DP)
• Common Remedies
– Cut back o...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Wetlands (WL)
• Shallow depressions that rece...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Wetlands (WL)
• Inflow
• Forebay
• Weir wall
...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Wetlands (WL)
22
Picture: VDEQ Stormwater Des...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Wetlands (WL)
Routine Deficiencies Observed:
...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Wetlands (WL)
24
Erosion on the main pool flo...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Wetlands (WL)
• Common Remedies
– Remedies ar...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities
We will finish up Above Ground Facilities
aft...
A Fairfax County, VA, publication
Department of Public Works and Environmental Services
Working for You!
Stormwater Mainte...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Course Schedule
AM session (includes two 15 minute breaks)
– History ...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Infiltration Trenches (TR)
Provides some quan...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Infiltration Trenches (TR)
Properly Functioni...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Infiltration Trenches (TR)
• Topsoil and sod ...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Infiltration Trenches (TR)
Sediment Accumulat...
Stormwater Maintenance Awareness Training
Above Ground Facilities-Infiltration Trenches (TR)
Plantings & Overgrown Vegetat...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Infiltration Trenches (TR)
Turf Covered TRs
3...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Infiltration Trenches (TR)
Cleanouts/Observat...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Infiltration Trenches (TR)
• Common Remedies
...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Infiltration Trenches (TR)
• Common Remedies
...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Permeable Pavement (PP)
• Alternative paving ...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Permeable Pavement (PP)
• Observation well
• ...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Permeable Pavement (PP)
40
Picture: VDEQ Stor...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Permeable Pavement (PP)
Routine Deficiencies ...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Permeable Pavement (PP)
Routine Deficiencies ...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Permeable Pavement (PP)
Outfall Structure/Und...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Permeable Pavement (PP)
• Common Remedies
– R...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Permeable Pavement (PP)
• Common Remedies
– R...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Rooftop Detention (RT)
• Designed to slow the...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Rooftop Detention (RT)
• Roof drain
• Debris ...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Rooftop Detention (RT)
Properly Functioning E...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Rooftop Detention (RT)
Routine Deficiencies O...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Rooftop Detention (RT)
Parapet Walls, Vegetat...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities-Rooftop Detention (RT)
• Common Remedies
– Re...
Stormwater Maintenance Awareness Training
MSMD/DPWES
Above Ground Facilities
LUNCH!
Please be back & ready to start at 1:0...
Nächste SlideShare
Wird geladen in …5
×

Stormwater Maintenance Awareness Above Ground Facilities parts 1 and 2

1.304 Aufrufe

Veröffentlicht am

The Stormwater Maintenance Awareness Training course identifies common types of above ground facilities.

Veröffentlicht in: Umweltschutz
  • Als Erste(r) kommentieren

Stormwater Maintenance Awareness Above Ground Facilities parts 1 and 2

  1. 1. A Fairfax County, VA, publication Department of Public Works and Environmental Services Working for You! Stormwater Maintenance Awareness Training For privately maintained stormwater management facilities Maintenance and Stormwater Management Division (MSMD) Winter 2018
  2. 2. Stormwater Maintenance Awareness Training MSMD/DPWES Course Schedule AM session (includes two short breaks) – History of SWM and regulations – County inspection basics – The inspection report and MAR – Common SWM/BMP types • Common maintenance items-General – Common SWM/BMP types, deficiencies, and remedies • Above Ground Facilities 12:00-1:00 PM Lunch PM session (includes two short breaks) – Common SWM/BMP types, deficiencies, and remedies • Below Ground Facilities • Vegetative Practices – Closing remarks/questions 2 NOTE: All pictures, unless noted, are the property of Fairfax County.
  3. 3. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-General Safety 3 The County’s private inspection program does NOT allow for Confined Space Entry! Please ensure you are properly certified, have the proper entry permits, and are appropriately equipped before entering any applicable confined space!
  4. 4. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Ponds (WP, DP) • Wet Ponds (WP) and Dry Ponds (DP) are both depressed basins providing temporary storage for stormwater runoff. – WP are designed to have a permanent pool. – DP basins are designed to usually be dry, except when handling runoff. • Some DP basins may have permanent wet features, including deep cells, micropools, or sediment forebays. 4
  5. 5. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Ponds (WP, DP) WET POND COMPONENTS Profile of a typical WP Plan view of WP with sediment forebay and WL 5 Pictures: VDEQ Stormwater Design Specification No. 14, Wet Pond, Version 1.9, 3/1/11, Figure 14.1 “Wet Pond Design Schematics”
  6. 6. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Ponds (WP, DP) DRY POND COMPONENTS - Under the new Virginia SWM regulations, Extended Detention Ponds constructed after July 1, 2014 must include, at a minimum, the following components: • Sediment Forebay • Micropool 6 Pictures: VDEQ Stormwater Design Specification No. 15, Dry Pond, Version 1.9, 3/1/11, Figure 15.1 “Typical Extended Detention Pond Details”
  7. 7. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Ponds (WP, DP) DRY POND COMPONENTS - Dry Ponds constructed prior to July 1, 2014 are likely to have a simpler profile: 7 LEFT Picture: Page 62, http://www.novaregion.org/DocumentCenter/Home/View/1679
  8. 8. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Ponds (WP, DP) Routine Deficiencies Observed: Algae/Turbidity (WP only) 8 Trash rack crushed/damaged, requires replacement BELOW: High turbidity caused by suspended materials (soil, sediment, microbes, etc.) can harm aquatic life, create clogging concerns, and cause build-up. ABOVE: Algal bloom and growth can create significant water quality issues, impacting plant and wildlife, as well as creating visual and odor concerns.
  9. 9. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Ponds (WP, DP) Water level inconsistent with plans (WP only) 9 s
  10. 10. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Ponds (WP, DP) Trickle Ditches (DP only) 10 TOP RIGHT: Erosion and trenching along the trickle ditch, with some overgrown vegetation BOTTOM RIGHT: Significant spalling and deterioration of concrete in trickle ditch TOP LEFT: Obstruction or blockage in trickle ditch BOTTOM LEFT: Trickle ditch with some significant sediment and debris accumulation
  11. 11. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Ponds (WP, DP) Dam/Berm - Erosion and Failure NOTE: Remaining slides apply to both WP and DP 11 BELOW: Erosion of the dam face has led to significant piping (formation of water channels throughout embankment interior) and blockage, requiring immediate attention RIGHT: (Both pictures are from same site) Significant erosion and sloughing of the dam/berm, requiring immediate attention as this can lead to dam failure with increasing area damage
  12. 12. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Ponds (WP, DP) Dam/Berm - Cave-Ins and Animal Holes 12 LEFT: Dam/berm cave-ins, possibly caused by pipe joint separation, seepage, and/or problems with the interior dam fill RIGHT: Animal holes on top and side slope of dam/berm
  13. 13. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Ponds (WP, DP) Vegetation & Trash/Debris Accumulation 13 RIGHT BOTTOM: Sediment accumulation and debris reduces the holding capacity of the pond and its ability to treat the designed volume of stormwater runoff. BELOW: Large appliance dumping and other trash/debris accumulation from upstream can critically impact facility function & create problems downstream. RIGHT TOP: The riser structure has overgrown vegetation around it.
  14. 14. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Ponds (WP, DP) Trees and Woody Vegetation on Dam/Berm 14 Back Face Control Structure No trees or woody vegetation should be on any side of the dam/berm embankment (face, back, top, etc.) *Check site plans for specifics. Pond Floor
  15. 15. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Ponds (WP, DP) Riser/Trash Rack 15 Significant sediment & debris accumulation and trash rack damage-requires cleaning and trash rack replacement Trash rack & low-flow orifice plate, if required by site plans, must be installed flush with the riser structure, with no gapping. Here, debris must be cleared, then low-flow orifice plate & trash rack properly re- installed. Missing low-flow orifice plates are a common issue. Inside riser blockage
  16. 16. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Ponds (WP, DP) Outfalls 16 Undermining below outfall pipe (can be related to separation at last joint of PSP, etc.) Downstream blockage or impending blockage within 20 feet of outfall structure (potential back up and impact to water flow from the PSP) Erosion at curb cut inflow area, needs repair
  17. 17. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Ponds (WP, DP) • Common Remedies – Algal bloom, turbidity, and water level inconsistent with plans (WP only) • Investigate and resolve cause(s), if at all possible – Remove all flow blockages as well as any additional trash, debris, and accumulated sediment – Repair/replace any damaged/missing components • Components vary by facility type and design, and they can range from parts (trash racks, well caps, etc.) to structural (walls, concrete, etc.) to environmental materials (soil, gravel, etc.) – Check approved site plans for specific facility requirements 17
  18. 18. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Ponds (WP, DP) • Common Remedies – Repair/replace any damaged/missing components (continued) • For damaged/misaligned pipes: – Reinforce/repair, if possible (Internal bands and gaskets) – Slip-line pipes when possible, as this may be more cost effective – Excavate and replace/reseal, if first two options are not possible – Rebuild/stabilize any areas with erosion, cave-ins, and bare spots: • Cave-ins require additional investigation to determine cause and prevent re-occurrence • Fill-in/stabilize any animal holes, per plan maintenance guidelines, to discourage occupancy and re-occurrence 18
  19. 19. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Ponds (WP, DP) • Common Remedies – Cut back overgrown vegetation around facility structures to facilitate access and proper function (WP/DP have special requirements, as noted below) • Remove all trees and woody vegetation from the entire dam embankment: face, back, top, etc. – Check plans for a ‘Planting Plan’ which may have allowed plantings on the dam embankment • Remove overgrown vegetation – Within 25’ radius of channels – Within 10’ from the heel of dam, 10’ from toe of dam – Within inflow/outlet channels – Other areas, as needed, for facility access 19
  20. 20. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Wetlands (WL) • Shallow depressions that receive stormwater for water quality treatment by providing an ideal environment for: – Long residence time – Gravitational settling – Biological uptake – Microbial activity • Stormwater management benefits: – Nutrient load removal and reduction • Nitrogen • Phosphorus • Sediment 20 – Runoff volume reduction – Channel protection – Flood mitigation Properly Functioning Example:
  21. 21. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Wetlands (WL) • Inflow • Forebay • Weir wall • Permanent pool • Low flow orifice • Riser • Embankment • Outfall • Emergency spillway • Micro-topographic features • Tree peninsulas • High and low marshes • Micropools • Deep pools 21 Picture: VDEQ Stormwater Design Specification No. 13, constructed Wetlands, Version 1.9, 3/1/11, Figure 13.1 “Plan and Cross Sections of Constructed Wetland Level 1 and Level 2 configurations” WETLAND COMPONENTS
  22. 22. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Wetlands (WL) 22 Picture: VDEQ Stormwater Design Specification No. 13, constructed Wetlands, Version 1.9, 3/1/11, Figure 13.1 “Plan and Cross Sections of Constructed Wetland Level 1 and Level 2 configurations”
  23. 23. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Wetlands (WL) Routine Deficiencies Observed: • Clogging of pipes from sediment, vegetation and debris – If low flow orifice is clogged, it can result in a rapid change in wetland water elevations. • Sedimentation accumulations in forebays and micropools • Erosion and braiding (channel separation and intermixing, sometimes with formation of deposited bars or islands) • Vegetation Issues – Growth over access points – Invasive species – Dead, dying, missing vegetation – Bare spots – Trees and woody vegetation on dam embankment 23
  24. 24. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Wetlands (WL) 24 Erosion on the main pool floor Damaged wetland habitat vegetation Sediment and debris in upstream inflows Sediment accumulation in forebays
  25. 25. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Wetlands (WL) • Common Remedies – Remedies are the same as for WP/DP (please refer to slides 16-18) – Additional vegetative concerns specific to wetlands: • Remove any non-spec vegetation, especially if it impacts the health and function of the facility, as designed • Replace/replant any dead, dying, or missing wetland vegetation per approved site plans – Cut back overgrown vegetation around facility structures to facilitate access and proper function (WL have special requirements, as noted below) • Remove all trees and woody vegetation from the entire dam embankment: face, back, top, etc. – Check plans for a ‘Planting Plan’ which may have allowed plantings on the dam embankment • Remove overgrown vegetation – Within 10’ of control structure – Within 5’ of all other structures – Within inflow/outlet channels – Other areas, as needed, for facility access 25
  26. 26. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities We will finish up Above Ground Facilities after a short BREAK… 26
  27. 27. A Fairfax County, VA, publication Department of Public Works and Environmental Services Working for You! Stormwater Maintenance Awareness Training For privately maintained stormwater management facilities Maintenance and Stormwater Management Division (MSMD) Winter 2018
  28. 28. Stormwater Maintenance Awareness Training MSMD/DPWES Course Schedule AM session (includes two 15 minute breaks) – History of SWM and regulations – County inspection basics – The inspection report and MAR – Common SWM/BMP types • Common maintenance items-General – Common SWM/BMP types, deficiencies, and remedies • Above Ground Facilities (the rest of the story….) 12:00-1:00 PM Lunch PM session (includes two 15 minute breaks) – Common SWM/BMP types, deficiencies, and remedies • Below Ground Facilities • Vegetative Practices – Closing remarks/questions 28 NOTE: All pictures, unless noted, are the property of Fairfax County.
  29. 29. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Infiltration Trenches (TR) Provides some quantity control & treats runoff through filtration/infiltration 29 May be designed to treat surface runoff or piped drainage (downspouts)
  30. 30. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Infiltration Trenches (TR) Properly Functioning Examples: (Typical single-family residential lot facilities) 30 LEFT: Picture shows a gravel infiltration trench with a cleanout and observation well, during a soil probe test. A soil probe is pushed into the underlying gravel layer to determine the topsoil depth and confirm facility is “per design”. Sod cover
  31. 31. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Infiltration Trenches (TR) • Topsoil and sod cover (optional) • Observation well with metal cap with lock • Overflow berm • Pea gravel or river stone • Filter fabric layer • Aggregate (1.5 in. – 3.5 in. diameter) • Sand bed (6-8 in. deep) • Perforated underdrain (optional) 31 Picture: VDEQ Stormwater Design Specification No. 8, Infiltration Practices, Version 1.9, 3/1/11 INFILTRATION TRENCH COMPONENTS
  32. 32. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Infiltration Trenches (TR) Sediment Accumulation & Curb Cuts 32 TOP LEFT: Some debris and sediment on surface at curb cut BOTTOM LEFT: Curb cut blocked (remove wheel stop) TOP RIGHT: Surface debris & sediment accumulation BOTTOM RIGHT: Sediment accumulation in gravel bed Routine Deficiencies Observed
  33. 33. Stormwater Maintenance Awareness Training Above Ground Facilities-Infiltration Trenches (TR) Plantings & Overgrown Vegetation 33 Downed tree limb with deep- rooted/overgrown vegetation Overgrown vegetation within the limits of a gravel bed trench may indicate sediment accumulation, as plants do not tend to grow in clean gravel. Unauthorized plantings MSMD/DPWES
  34. 34. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Infiltration Trenches (TR) Turf Covered TRs 34 Some trenches may have turf and topsoil, covering the gravel bed; however, turf is not automatically acceptable. ALWAYS refer to the approved site plan! • A soil probe test checks the gravel layer (refer to slide 4). • Water usually reaches the gravel bed through underground PVC pipes connected to the roof drain downspouts. Common issues include: • Missing underground gravel beds • Disconnected roof downspouts draining overland instead of via an underground pipe • Bare spots/exposed soil in turf covering • Missing berms or observation wells
  35. 35. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Infiltration Trenches (TR) Cleanouts/Observation Wells 35 Other common issues: • Caps stuck/not removable • Clogged cleanouts • Presence of standing water in the cleanout Broken/damaged well cap Missing cap
  36. 36. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Infiltration Trenches (TR) • Common Remedies – Standing water after 48 hours: • Underdrain may need to be flushed and re-checked – Remove all flow blockages as well as any additional trash, debris, and accumulated sediment • Special attention should be given, as required to gravel beds (surface and within gravel pores) and may require removal/replacement of clogged sections of gravel • Fully remove any plants growing in the accumulated sediments – Full removal includes eliminating roots and supporting soil/sediment from the gravel bed, as spraying weed killer is not a sufficient treatment solution – Rebuild/stabilize any areas with erosion, cave-ins, and bare spots: • Cave-ins require additional investigation to determine cause and prevent re-occurrence 36
  37. 37. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Infiltration Trenches (TR) • Common Remedies – Repair/replace any damaged/missing components • Components vary by facility type and design, and they can range from parts to structural to environmental materials (see prior noted examples) – Check approved site plans for specific facility requirements • For damaged/misaligned pipes: – Reinforce/repair, if possible (Internal bands and gaskets) – Slip-line pipes when possible, as this may be most cost effective – Excavate and replace/reseal, if first two options are not possible – Cut back overgrown vegetation around facility structures to facilitate access and proper function 37
  38. 38. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Permeable Pavement (PP) • Alternative paving surface which treats runoff through filtration (voids in paved surface), temporary storage (underlying stone reservoir), and infiltration – Includes permeable pavement, pervious concrete, porous asphalt, and permeable pavers – PP promotes a high degree of runoff volume reduction & nutrient removal – Primarily used on commercial, institutional, & residential sites 38 Properly Functioning Examples:
  39. 39. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Permeable Pavement (PP) • Observation well • Perforated underdrain • Geotextile (optional) • Bedding Course • Aggregate base • Uncompacted subgrade soil • Permeable joint material (for PICP) 39 PERMEABLE PAVEMENT COMPONENTS
  40. 40. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Permeable Pavement (PP) 40 Picture: VDEQ Stormwater Design Specification No. 7, Permeable Pavement, Version 1.8, 3/1/11, Figure 7.1 (as noted) PERMEABLE PAVEMENT COMPONENTS
  41. 41. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Permeable Pavement (PP) Routine Deficiencies Observed Pervious Layer 41 Sediment/Silt Weeds/overgrown vegetation Deterioration &/or cracks in pervious layer
  42. 42. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Permeable Pavement (PP) Routine Deficiencies Observed Pervious Layer 42 Asphalt Sealed Pavers Clogged
  43. 43. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Permeable Pavement (PP) Outfall Structure/Underdrain 43 Damaged underdrains Clogging and/or a potential blockage in the outfall structure/underdrain Blockage in the underdrain
  44. 44. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Permeable Pavement (PP) • Common Remedies – Remove all flow blockages as well as any additional trash, debris, and accumulated sediment • Perform a thorough restorative vacuum sweep of paved surface • Investigate the causes of any blockages to prevent re-occurrence, if at all possible. – Repair/replace any damaged/missing components • Components vary by facility type and design, and they can range from parts to structural to environmental materials (see prior noted examples) – Check approved site plans for specific facility requirements • Specific to this facility type: any damaged, cracked, or failing pavers or paved sections 44
  45. 45. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Permeable Pavement (PP) • Common Remedies – Rebuild/stabilize any areas of erosion: • Adjoining land erosion can silt in permeable pavement – Remove vegetation in permeable pavement to facilitate proper function • Remove any non-spec vegetation, especially if it impacts the health and function of the facility, as designed. – Sealed permeable pavement requires a complete replacement 45
  46. 46. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Rooftop Detention (RT) • Designed to slow the flow from the roof through short-term ponding on the roof surface 46 Properly Functioning Examples of Rooftop Detention Devices: Ring with 1” holes Slotted square detention device Adjustable detention device Custom devices
  47. 47. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Rooftop Detention (RT) • Roof drain • Debris cage • Detention cage • Parapet wall • Scupper • Roof access (varies) 47 ROOFTOP DETENTION COMPONENTS
  48. 48. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Rooftop Detention (RT) Properly Functioning Examples: Scuppers convey emergency overflow off rooftop 48
  49. 49. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Rooftop Detention (RT) Routine Deficiencies Observed Scuppers and Adjustable Detention Devices 49 Scupper not providing proper water detention because it is level with roof Adjustable detention device opened too wide Detention device and debris cage missing Debris cage is damaged and detention device missing Incorrect number of drains and/or scuppers (usually too many)
  50. 50. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Rooftop Detention (RT) Parapet Walls, Vegetation, and Detention Devices 50 Parapet wall missing Debris Ponding Sediment Tree growing on roof surface
  51. 51. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities-Rooftop Detention (RT) • Common Remedies – Remove all flow blockages as well as any additional trash, debris, and accumulated sediment – Repair/replace any damaged/missing components • Components vary by facility type and design, and they can range from parts to structural to environmental materials (see prior noted examples) – Check approved site plans for specific facility requirements – Remove ANY vegetation around facility structures and on rooftop – Provide required detention flow rate • Replace any missing or damaged detention devices and debris cages • Re-adjust detention devices, as needed • Raise scuppers that are too low or provide detention at the scupper • Repair or install any missing parapet walls • Recalculate the flow based on the actual number of drains to attain the prescribed detention 51
  52. 52. Stormwater Maintenance Awareness Training MSMD/DPWES Above Ground Facilities LUNCH! Please be back & ready to start at 1:00 PM 52

×