Rock Trench (oil and grease control) 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. and photograph(s). 

An annual report shall be submitted via email to City Stormwater Management staff. The report shall include records of all inspections and maintenance performed for the year. Inspections shall be done every calendar year, with reports being submitted by June 1 of the following year. Annual reports for rock trenches do not require a P.E. stamp.

Maintenance Provisions

The Owner shall install and maintain a rock filled trench using three (3) inch diameter stone with filter fabric as shown on the approved plan set.  Said rock filled trench is installed for [infiltration, thermal control, sediment control or oil and grease] in the storm water runoff.   

Maintenance shall be, at a minimum include an annual visual inspection.  More specifically, debris shall be removed as needed and filter medium is to be replaced any time the filter medium appears to be 50% coated with oil or grease.  Excess sediment build up shall be removed. Owner shall maintain records of inspections, cleaning and replacement of the trench all in accordance with Chapter 37 of the Madison General Ordinances.