Permeable Pavement Typical Maintenance Requirements

Reporting Requirements

An initial installation certification (as-built) stamped by a Professional Engineer (P.E.) registered in the state of Wisconsin shall be submitted to the City Engineer upon completion of construction.  The as-built shall be of sufficient detail to show the system was properly constructed and is functioning as designed.  It shall include a statement by the certifying P.E. along with a marked-up drawing (if applicable), infiltration observation, and photograph(s). 

An annual report shall be submitted via email to City Stormwater Management staff. The report shall include records of all inspections, infiltration observation, and maintenance performed for the year. Inspections shall be done every calendar year, with reports being submitted by June 1 of the following year.

Operations Guidelines

The following activities shall be prohibited from occurring on the permeable pavement surface:

• Temporary or permanent stockpiling of soil or other material that can potentially cause or contribute to clogging.
• Application of pavement seal-coating.
• Application of sand for deicing.

Maintenance Provisions

Owner shall maintain records of installation, inspections, cleaning, replacement, and any other maintenance in accordance with Chapter 37 of the Madison General Ordinances and WDNR Conservation Practice Standard #1008 Permeable Pavement. Qualified personnel shall perform inspection, infiltration testing and maintenance work.

Inspection of the permeable pavement system shall be conducted at least once per year to evaluate the following:

• Pavement Condition. Inspect permeable pavement surfaces for settlement, deformation or cracking.
• Surface Infiltration. Inspect permeable pavement surfaces for sedimentation or evidence of ponding.
• Drainage. Inspect observation wells, if present, 72 hours after a rain event of 0.5 inches or greater to verify that the aggregate storage reservoir is draining down effectively.
• Outfalls. Inspect underdrain outfall locations for obstructions and erosion.
• Run-on Areas. Inspect run-on areas for adequate cover and stability.

Maintenance of the permeable pavement system shall be conducted as follows:

1. Clean the pavement surface using regenerative air or vacuum sweeping, at least twice per year (recommended in Spring and Fall). Include a log of your cleanings in your annual report.
2. If water ponding persists on the pavement surface after a storm event, clean the pavement surface to mitigate clogging.
3. Repair any settlement, deformations or cracking that are significant enough to adversely impact the water quality function of the system.
4. Repair blocked, restricted or eroding underdrain outfalls.
5. Repair and/or replant eroding run-on areas.
6. For permeable pavers/blocks with joints that are filled with aggregate:
   1. Replenish the joint aggregate in accordance with industry recommendations.
   2. If necessary, remediate the system by extracting accumulated debris and aggregate from the joints using a vacuum and re-filling the joints with new aggregate.
7. For porous asphalt and pervious concrete, repairs may be done with conventional impervious materials if the total impervious repair areas do not exceed 10% of the original permeable surface area and runoff from the repair areas will run on to adjacent permeable areas. The 10% threshold may only be exceeded if design calculations confirm that the system is still able to accept the full loading for which it was originally designed.

If the pavement surface infiltration rate is questionable at any time during the effective life of the pavement, the administering authority may require infiltration rate testing to verify that the surface infiltration rate is no lower than 10 in/hr. If the surface infiltration rate is lower than 10 in/hr, appropriate action shall be taken to restore the infiltration rate to an acceptable level based on the remaining effective life of the pavement.

If verification of in place pavement surface infiltration rates is necessary, conduct pavement surface infiltration rate testing per ASTM C1701 Standard Test Method for Infiltration Rate of In Place Pervious Concrete for pervious concrete and porous asphalt, ASTM C1781 Standard Test Method of Surface Infiltration Rate of Permeable Unit Pavement Systems for permeable pavers/blocks or other methods approved by the administering authority.