Annual Certification of Private Stormwater Facilities
The New Jersey Department of Environmental Protection requires municipalities to
"develop, update, implement and enforce a program to ensure adequate long-term
cleaning, operation and maintenance of stormwater facilities not owned or
operated by the Tier A Municipality, not subject to the conditions of another
NJPDES stormwater permit and constructed after February 7, 1984." Township
ordinance 2419 requires property owners to annually certify that their
stormwater systems are being maintained and are operating properly.
The Engineering Department maintains a list of properties required to
submit the certification - click here for the "Stormwater Certification List". Using the fillable forms on this website,
the certification may also be submitted to firstname.lastname@example.org.
Maintaining Your Stormwater System
Why is maintenance important?
Excess fertilizer, lawn chemicals, automotive products, pet waste, leaves, debris, litter and anything else that washes from the landscape are carried with each rain storm into drainage systems, some of which flow directly into area waterways. Stormwater facilities reduce the flow which allows for filtration of these pollutants before the stormwater enters our streams, rivers, lakes and bays. Consistent maintenance is critical to reduce the pollution of our waterways.
Types of Stormwater Facilities
Infiltration Trenches/Basins/Drywells are
stone-filled excavations or tanks that temporarily store stormwater runoff as
it soaks into the soil beneath it.
Detention Basins are man-made basins,
which detain water for specified periods of time after a storm and do not
contain a permanent pool of water. Water is impounded temporarily to allow
much of the sediment carried by the runoff to settle to the bottom.
Many of the pollutants, such as nutrients, are attached to sediment particles
and are also removed. No standing water should remain if the facility is
functioning properly. Do not fertilize detention basins.
(also known as wet ponds or stormwater ponds) have a permanent pool of water. Retention ponds are more effective at improving water quality than dry ponds because they allow more time for pollutant settling and removal.
are gently sloped areas of vegetation that slow the flow of runoff, channeling it to other facilities. Grassed swales are typically found in residential developments as an alternative to curb and gutter. Swale maintenance is typically the responsibility of the homeowner and includes mowing and periodic reseeding. Mowing the grass too short or applying lawn chemicals can negatively impact the performance of the swale. Do not fertilize swales that lead to detention areas or waterways.
Filter Strips and Buffers are areas of vegetation that remove pollutants in runoff as the water flows through it. Filter strips are similar to grass swales, only wider. Buffer areas can contain a variety of vegetation, including trees and shrubs. Do not fertilize filter strips and buffers.
Manufactured Treatment Devices (MTDs)
are equipment installations that require direct maintenance such as the replacement of filter membranes. MTD’s are highly effective installations when maintained.
Regular inspection of the stormwater facility is the first step. For large or complex systems, consider hiring a qualified professional to ensure proper functioning of the facility. Inspection is an easy and quick way to check operations in most cases.
Vegetation slows the velocity of runoff, filters sediment, and prevents erosion. Grass in and around facilities may be hardiest if maintained as an upland meadow, cutting no shorter than 6-8 inches. Maintaining a more manicured expanse of grass decreases the effectiveness of the facility. Consider wetlands plants that do not require mowing in place of grass and never fertilize vegetated areas that receive or convey stormwater.
The vegetation surrounding infiltration trenches or buffer strips also removes some sediment before the
stormwater enters the stormwater facility. If plants are damaged or become laden with sediment, they can no longer perform beneficially. Therefore, the condition of these areas should be closely monitored, and vegetation replaced if necessary.
Debris and litter
– trash and litter clogs outlet structures and pipes, damages vegetation, creates mosquito breeding, and excessive algae growth. Remove debris and litter regularly. If trash is a persistent problem evaluate upstream inlets and structures for retrofitting to stop trash from entering the system. Consult with a qualified professional to identify the best location to trap and collect debris before it enters.
such as valves, gates, pumps, fences, locks and access hatches should be maintained at all times. Design and site factors will determine the amount of maintenance that is necessary.
should be monitored and repaired when needed. Lawn mowing equipment often damages vegetation causing soil erosion. Adjust the frequency or method used to cut vegetation. Avoid maintaining detention basins as lawns and maintain as meadows instead with cutting limited to once or twice annually.
may be necessary from detention basins every 5-10 years depending on conditions. Sediment accumulates faster in infiltration facilities than detention basins and should be checked quarterly and cleaned often. Most infiltration trenches have a sediment trap or filter to remove some sediment before the stormwater enters the trench. Keeping this sediment filter clean is vital to ensuring the long-term performance of the infiltration trench. Follow cleaning procedures in the maintenance plan approved with the design.
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