Low Impact Development Training Maintenance & Monitoring: Environmental & Facility Managers...

Low Impact Development Training Maintenance & Monitoring: Environmental & Facility Managers

Presented by:

The Low Impact Development Center, Inc. A non-profit water resources and sustainable design organizationwww.lowimpactdevelopment.org

Copyright 2009 Low Impact Development Center, Inc.

Objectives

• Maintenance for Bioretention, Pavers, Green Roofs, Filter strips and buffers

• Corrective Actions• General Environmental Monitoring


• Regulatory requirement – NPDES MS4 permit– Other State storm water regulations (new)– Documentation may be required

• Necessary to continue function as designed• Proper maintenance lowers long term costs • Less costly to maintain than repair or replace

Maintenance Drivers


Maintenance – Bioretention

• Primary maintenance requirement - regular inspection and repair / replacement of damaged components

• Can be incorporated into regular landscaping maintenance contract, as the routine periodic maintenance for bioretention areas is similar to what is required of any landscaped area


Planting Maintenance

• Routine maintenance should include a biannual health evaluation of the plantings, and removal and replacement of any dead or diseased vegetation.

• The use of native plant species in the bioretention cell will reduce fertilizer, pesticide, water, and overall maintenance requirements.

• Level of pollutants in the soil can become toxic, impair plant growth




Planting maintenance

• Immediately after installation, water plant material for 14 consecutive days (unless sufficient natural rainfall).

• When trees have taken root, or at least by 6 months, remove stakes and wires

• Visually inspect vegetation for disease or pest problems at least once in the spring, once in the fall, and more frequently in the summer. If treatment is warranted, use the least toxic approach

• During extended drought, look for physical signs of stress (unrevived wilting; yellow, spotted or brown leaves; loss of leaves, etc.). Water in the early morning if needed

• Prune excess growth annually in the spring and throughout the growing season if desired. Trimmed materials may be recycled back in with replenished mulch or landfilled if there is a concern of heavy metals accumulation.

• Weed regularly, as necessary



Requirements Testing Remediation

Soil pH should be between 5.5 and 6.5.

Obtain a kit and instructions from the State Cooperative Extension Office.

Apply the necessary amount of limestone to get the pH in the correct range.

Soils• Visually inspect and repair erosion at inflow points once in the spring and once in the fall, at a minimum. • Use small stones to stabilize erosion along drainage

paths. • Check the soil’s pH once or twice a year. • Apply an alkaline product, such as limestone, if needed.



Soils - Maintain Infiltration Rates• Runoff from impervious surfaces is directed to bioretention

cells to infiltrate through the soil medium

• Once the infiltration capacity of the soil medium is exceeded, storm water begins to pool at the soil’s surface

• Ponding should only last 4-6 hours

• Mosquitoes larva need 4+ days of standing water


Soils – Corrective Action• Depending on pollutant loads, soils may need to be replaced within 5-30

years of construction.• If standing water consistently over 4-6 hrs:

– Clear the underdrain of potential clogs– Check filter fabric above the underdrain– Remove mulch and rake surface to remove surface blockages – Last resort - remove the soil mixture

• Before removing soil mixture, analyze for clay content and hazardous content

• If greater than 15% clay content, then:– Temporarily block end of discharge pipe, install appropriate E&S controls– Carefully dig up plants so that root systems are maintained (and return to cell

following soil replacement)– Remove soil and dispose appropriately as clean fill or in an approved landfill – Inspect pipe and gravel layer, if pipe is clogged, then wash the gravel layer

with a high-pressure hose – this should clean the pipe– Place new soil in the cell and replant vegetation




Mulch Layer• Uniformly applied approximately 2 to 3 inches deep. Do

not pile the mulch around trees or other plantings• Fresh bark mulch (either standard landscape fine

shredded hardwood mulch or hardwood chips). Make sure it is free from weed seeds, soil, roots or any other substance not consisting of bole, branch wood, or bark Do not use grass clippings as mulch

• Every 6 months, in the spring and fall, add a fresh mulch layer. Once every 2 to 3 years, in the spring, remove the old mulch layer before applying the new one


Description Frequency

1. Soil

a) Inspect and Repair Erosion Spring and fall

b) Check pH Once a year

2. Organic Layer

a) Re-mulch any void areas As needed

b) Add new mulch layer Spring and fall

c) Remove old mulch layer Three (3) years

3. Plants

a) Water plant material for fourteen consecutive days after planting has been completed unless there is sufficient natural rainfall

Immediately afterCompletion ofproject

b) Remove stakes and wires after six months After rooting

c) Inspect for disease/pest problems Spring/summer/fall

d) Treatment of diseases As needed, refer tomanufacturer

Maintenance Schedule – Bioretention


3. Plants (continued)

e) Removal and replacement of all dead and diseased vegetation considered beyond treatment

Spring and fall

f) During times of extended drought, look for signs of stress Water as needed.

Summer

g) Weed and prune excess growth Spring/summer

h) FertilizeAs needed, refer to manufacturer

i) Remove tags After warranty

4. General

a) After major rainstorms, inspect site and make sure drainage paths are clear and that ponding water dissipates over time. Clear the drainage path of any accumulated sediment or debris. Seek remediation if drawdown times are consistently much longer than 4-6 hours

After major rainstorms

Maintenance Schedule – Bioretention


Maintenance – Permeable Pavers

• Primary maintenance requirement - clean the surface drainage voids

• Can be incorporated into regular street sweeping program

• Annual inspections


• Inspections • Routine maintenance is key:

– Conventional street sweepers equipped with vacuum sweepers and high-pressure water can used to restore permeability

– Street sweeping frequency varies depending on drainage area inputs (leaf debris, erosion, etc.). An active street sweeping program in the site’s drainage area will also help to prolong the functional life of the pavement

– If necessary, add additional gravel chips to fill pore spaces after vacuum sweeping

• In case of localized settling, individual paver blocks can be removed, new gravel added, and the blocks replaced



• Restrict use by heavy vehicles

• Limit use of de-icing chemicals and sand

• Implement stringent sediment control plan

• Failure of systems:– poor design– inadequate construction

techniques– low permeability soils– heavy vehicular traffic– resurfacing with nonporous

materials



Maintenance Schedule Permeable Pavers


Initial Inspections Monthly for first several months

following construction

Vacuum sweeping and high

pressure hosing

4 times/year

Encourage active street cleaning

in the site’s area

Regularly

Annual inspections Yearly, after large storms

Fill potholes and cracks As needed

Address spot-clogging problems

by drilling holes

As needed


Maintenance – Permeable Pavement

Routine Maintenance• Similar to permeable

pavers • Recommended: Vacuum

sweep twice per year


Maintenance – Permeable Pavement

Corrective Action• Fill potholes and

cracks with permeable patching mixes

• Fix spot clogging by drilling ~0.5-inch holes through the porous pavement layer every few feet


• Virtually maintenance free• Periodic inspections of system components• Most important - ensure spigot is set to slowly

release the barrel’s water

Maintenance – Rain Barrels & Cisterns


• Bimonthly inspection:– rain barrel is free of debris– filtration screen and downspout not clogged– overflow system properly directing the water away from

siding and foundations and not causing erosion problems

– mosquito screen properly installed

• Once a year, wash the barrel with mild (preferably biodegradable) soap and water

Maintenance – Rain Barrels & Cisterns


Corrective Action• There are few mechanical parts on cisterns or rain barrels • Spigot, valve, and screen replacements can be ordered

from the manufacturer • Cracked rain barrel = replace rain barrel

• Large cisterns constructed out of materials such as metal or concrete may need repairs to walls by parging (for concrete) or welding (for metal)

Maintenance Schedule – Rain Barrels & Cisterns



Make use of the stored water! Regularly

Check for clogging of the entrance/outlet points Every other month

Check for proper diversion of the overflow system Every other month

Check for proper installation of the mosquito screenEvery few weeksin the summer

Wash the barrel with mild soap and waterAnnually,preferably in thespring

Prepare the system for winter conditions Pre-freezing

Maintenance Schedule – Rain Barrels & Cisterns


• The maintenance requirements for street tree-box filters are similar to those of other bioretention devices, although less complicated

Maintenance – Street Tree-Box Filter


Inspections• Bimonthly• If possible, conduct during or immediately after a

rain event• Debris removal:

– Inspect system and clear drainage path of accumulated leaves, debris, and trash

– Remove accumulated materials on the top layer of the soil media, test, and dispose

– Inspect discharge pipe for clogging and clean if necessary




Planting Maintenance

• Same maintenance as bioretention cells

Soils Maintenance• Same maintenance as bioretention cells• Runoff bypassing the tree-box = clogged inflow area, or

reduced infiltration properties of soil mixture• Soils analysis, disposal requirements, and corrective

measures are the same as bioretention cells • For remediation assistance, contact Americast at

(800) 999-2278 or (804) 798-6068


• First two years of maintenance typically included with the purchase of single and multiple-unit tree box filters – These would include removal of trash, debris and sediment,

replenishment of the mulch, and care or replacement of plants

• Annual maintenance = $500 per unit (performed by the manufacturer) or $100 per unit (performed by the owner) (sample cost estimate based on the Filterra™ Stormwater Bioretention Filtration System.)



Corrective Actions• Plants may have to be replaced because:

– they have overgrown the filter– environmental stress– they are mistaken as weeds growing through the

grate, and are removed



1) Overall system

a) Inspect and clear drainage paths Every other month

2) Plants

a) Water plant material for fourteen consecutive days after planting

has been completed unless there is sufficient natural rainfall

Immediately after completion ofproject

b) Inspect for disease/pest problems Spring/summer/fall

c) Treatment of diseases As needed, refer to manufacturer

d) Removal and replacement of all dead and diseased vegetation considered beyond treatment

Spring and fall

e) During times of extended drought, look for signs of stress. Water

as needed. Summer

f) Weed and prune excess growth Spring/summer

3) General

a) During major rainstorms, inspect site and make sure that infiltration is occurring as expected.

Every other month.

b) Clear the top layer of soil of accumulated material As needed

c) Clean the drainage pipes As needed

d) Seek remediation if infiltration function is not adequate after cleaning efforts

As needed

Maintenance Schedule - Street Tree-Box Filter


Maintenance - Dry Wells

• Minimal maintenance:– Clearing the rain gutters of

debris that could clog the downspout

• Corrective Actions: – Can clog over time if there

is extensive loading of fine-grained sediment

– Standing water at the surface indicates clogging– Dig out gravel, then excavate to remove sediment and uncover a

layer of soils that has sufficient infiltration capacity


Maintenance - Filter Strip

• Incorporate into landscaping contract • Inspect twice annually for erosion or damage to vegetation• Additional inspections after periods of heavy runoff • Requires mowing, irrigation, and weeding • Mowing may only be necessary 1x or 2x per year for safety

and aesthetics or to suppress weeds and woody vegetation • Periodic litter removal, and always prior to mowing


Maintenance - Vegetated Buffers

Maintenance Program• Monitor and manage to maintain maximum water quality benefits

and, where desired, wildlife habitat benefits• Inspections – at least annually, and always within a few days after

severe storms. Look for evidence of sediment deposition, erosion, or development of concentrated flow channels

• Aggressive weed and invasive species control• Avoid working in riparian area between April 15 and August 15, when

a variety of animals are bearing their young

• Corrective Actions– If the buffer width is sufficient,

Changes in hydrology, drought, over-grazing or natural disasters such as flooding or fire may require the replanting or reestablishment of the buffer


Maintenance - Grassed Swales

Maintenance Objectives:• Keeping up the hydraulic and removal efficiency of the channel• Maintaining a dense, healthy grass cover

Maintenance Program:• Periodic mowing (with grass never cut shorter than the design flow

depth)• Weed control• Watering during drought conditions• Reseeding of bare areas• Clearing of debris and blockages

Corrective Actions:• Remove cuttings from the channel• Remove accumulated sediment • Avoid applying fertilizers and

pesticides


Maintenance - Infiltration Trenches

Maintenance Objectives:• Prevent clogging, which may lead to trench failure

Maintenance Program:• Inspect annually• Monitor observation well to confirm

trench is draining properly• Inspect after large storm events• Remove accumulated debris or

material • Stabilize surrounding areas to

eliminate the potential for sediment clogging

Corrective Actions:• If infiltration trench fails, remove clogged stone and sediment• Wash stone to remove sediment and replace


Maintenance - Green Roof

• Maintenance requirements for a properly installed, well established vegetated roof are minimal:

• Inspection of roof membrane, the most crucial element of a vegetated roof

• Inspection and preventive maintenance of the drainage layer flow paths


Maintenance - Green Roof

Corrective Actions• More complex systems may have monitoring devices

incorporated into the membrane• Leak detection systems can be brought to the site to

locate breaches in the membrane• The soil media can be removed & the membrane repaired • Long periods of drought or

loss of soil to high winds may require replacement of the media or replanting

• Schedule supplemental watering during drought periods, or install an irrigation system


Stormwater Management Feature Maintenance Contracting and $

• Sustainment (UT/SRM) funds must be used, NOT Environmental

• Enter your SW features into iNFADS- NAVFAC Portal- Account request

• Partner with PW to get your SW features maintained

• SOW, GCE• Landscaping contract, BOS contract, new

Regional Stormwater Maintenance Contract (?)

iNFADS


Monitoring Programs

• Not typically a regulatory requirement

• Potential requirement for discharges to sensitive or impaired waters

• Monitoring plan shaped by regulatory requirements, site characteristics, parameter(s) of concern, and use of the data


Water Quantity Monitoring

Monitor the effectiveness of LID features either on a small scale (individual features) or large scale (stream flow):

Small Scale Manual or automatic sampling methods can be used to calculate flow rates upstream and downstream of a LID feature, based on the depth measured using a weir or a rate of flow measured using a conveyance device.

Large ScaleWhere LID features are being installed as retrofits in already developed areas, the effectiveness of the retrofits can be assessed by comparing pre-LID and post-LID flow rates downstream.


Water Quality Monitoring

• The same pre- and post-LID samples taken for small scale water quantity monitoring can be used for water quality monitoring

• The Nationwide Urban Runoff Program (NURP) has identified the following “standard pollutants characterizing urban runoff”:

Pollutant Abbreviation

Suspended Solids Concentration SSC

Biochemical Oxygen Demand BOD

Chemical Oxygen Demand COD

Copper Cu

Zinc Zn

Total Phosphorous TP

Soluble Phosphorus SP

Total Kjeldahl Nitrogen TKN

Nitrate + Nitrite NO2 + NO3

Water Quality Monitoring Parameters


Training

• Stormwater Training for facility personnel• ECATTS

• Web-based environmental training by media• Approximately 20-min each• Courses:

• Stormwater – Basic Information• Stormwater – Comprehensive Overview• Wetlands• Spill Prevention Control and Countermeasures• Spill Response and Notification

• http://navfac.ecatts.com• Password = “navfac”

• Stormwater Training for Facility Managers

http://navfac.ecatts.com/

ECATTS

Low Impact Development Training Maintenance & Monitoring: Environmental & Facility Managers...

Documents

Transcript of Low Impact Development Training Maintenance & Monitoring: Environmental & Facility Managers...