Up-Flo
®
Filter Operation and Maintenance Manual
Hydro International
(Stormwater), 94 Hutchins Drive, Portland ME 04102
Tel: (207) 756-6200 Fax: (207) 756-6212 Web: www.hydro-int.com
First Year Inspection and Maintenance
The frequency of inspection and maintenance can be determined in the field after installation. The frequency of ongoing maintenance
needs is based on site characteristics such as contributing area, types of surfaces (e.g., paved and/or landscaped), site activities (e.g.,
short-term or long-term parking), and other site maintenance (e.g., sanding and sweeping). At a minimum, inspection and maintenance
should be conducted at intervals of no more than six months during the first year of operation. Maintenance personnel should observe
and record pollutant accumulations during the first year of service in order to benchmark the maintenance intervals that will later be
established for the site. Pollutant accumulations should be measured or monitored using the following procedures:
•
Measurement of sediment depth in the sump: A minimum of 8 inches (20 cm) should separate the Drain Down Filter inlet from stored
sediment in the sump in order to minimize sediment migration into the Drain Down Filter. A simple probe, such as the Sludge-Judge
®
,
can be used to determine the depth of the solids in the sump. In a typical 4-ft
(1.2m) diameter manhole installation, the sediment depth should be no more
than 16 inches (41 cm).
•
Maintenance personnel should then enter the structure, remove the Media
Pack from one of the Filter Modules, and weigh the Media Bags. Media Bags
with a wet weight of approximately 40 lbs (18 kg) or more are an indication
that the filter media has become full and that the Media Packs in all of the
Filter Modules will require replacement (Fig.4).
Minimum filtration rate is
generally reached when the Media Bags have accumulated approximately 20
lbs (9 kg) of sediment. Determining the amount of accumulated sediment will
be accomplished by removing both of the Media Bags from one of the Media
Packs and weighing the bags separately. Since a new Media Bag weighs
approximately 30 lbs (14 kg) wet, the difference in weight will approximately
equal the weight of solids that have accumulated in the bag. A spent Media
Bag weighs approximately 50 lbs (23 kg) wet.
•
Measurement of oil layer on water surface: Since water in the Up-Flo
®
vessel
drains down to an elevation below the bottom of the Filter Modules when the
system is idle, the amount of accumulated oil must be minimized so that oil is
not entrained in the Media Pack when stormwater begins to fill the vessel at
the start of a storm event. Oil accumulation should be limited to 1.5 inches (4
cm) or less. Probes can be used to measure oil thickness.
•
Monitoring for Drain Down Filter clogging: The water level in the Up-Flo
®
Filter should be monitored to ensure that the Drain Down Filter is operating
properly. The Drain Down Filter is designed to lower the water level in the Up-
Flo
®
vessel to an elevation below the bottom of the Filter Modules between
storm events. Periodically conduct an inspection one to two days after a
storm event during the first year of operation. Approximately 36 hours after a
1-in (2.5-cm) rainfall, the water level inside the vessel should have dropped
to a point where it is equal with the base of the Filter Modules. If the water
level has not reached that point, then the Drain Down Filter has either become clogged or blinded by trash or debris (Fig.5 a and b).
If there is no evidence of trash or debris around the Drain Down Filter inlet, then it has likely become clogged with particles.
•
Monitoring for slime and debris covering the Flow Distribution Media or Angled Screens: After removal of the Media Bags, the bottom
Flow Distribution Media should be removed and inspected to determine if it is coated with slime or debris. Similarly, the Angled
Screen should be inspected for blockages and ragging.
Page | 6
Fig.4 a) A new Media Bag of Hydro Filter Sand. b) A spent
media bag of Hydro Filter Sand.
a .
b .
