1. science
2. ecology
3. pollution

STORMWATER BMP SURVEY PROCEDURES
BIRD RIVER RESTORATION CAMPAIGN
The purpose of the survey is to identify stormwater ponds and other Best Management Practices (BMPs)
located in the 26 square-mile Bird River watershed which are in need of maintenance. In other
Maryland watersheds, up to half of all existing BMPs have failed due to a lack of maintenance.
Through this survey and your efforts we’ll get failing BMPs fixed so they can once again protect Bird
River from excessive pollution. You have the choice of doing this either as: a) part of a Road Trip, b)
on your own or c) with a friend. There could be as many as 490 existing BMPs in the watershed. We’ll
be focusing on those BMPs which are most effective in keeping pollution out of our River and her 90
miles of tributary streams. These BMPs are deemed High Priority. There are about a hundred of the
High Priority BMPs listed for our watershed. However, a portion of these BMPs may not have been
built yet as indicated by unbuilt or Null under date built in the listings referenced below.
A. Go to the Bird River Restoration Campaign website at: restorebirdriver.org;
B. Along the left margin, click: Stormwater Ponds & Other BMPs;
C. Scroll down to Resources where you’ll find a map and listings of existing BMPs along with various
guidance documents;
D. For the time being we suggest focusing on the High Priority BMPs;
E.
Click on the Map of Bird River Watershed BMPs. The High Priority BMPs have the green
markers, not the red. Pick out several BMPs you’d like to evaluate, perhaps those near your home;
F.
Select BMPs NOT bracketed with parenthesis ( ), which have already been evaluated;
G. While still viewing the map, zoom in so you can see roads and other landmarks allowing you to
figure out where each BMP is located.
H. Print out a detailed map of each BMP which you can use to find the BMP in the field;
I.
Go to one of the two BMP listings. Referring to the BA- identifier (ID) determine the type of each
BMP. However, there are BMP type errors in the listing. You may arrive expecting to see a pond
when in fact the BMP is a sand filter. See the guidance photos following this page to determine
BMP type in the field;
J.
Download the appropriate factsheet for each type of BMP you’ve selected. Be certain to read each
factsheet before visiting BMPs;
K. Complete a Bird River Stormwater BMP Checklist in the field for each BMP you evaluate; and
L.
At your earliest opportunity, transfer your field data to the online form posted at:
ceds.org/birdriver/bmpform
For further detail contact John Smith at 410-335-6089 or John@birdriver.org. Consider reading
Auditing Chesapeake Bay Watershed Stormwater Best Management Practices and viewing Assessing
Stormwater BMPs for Maintenance Needs, both of which are in the Resources section of the
Campaign’s website.
IDENTIFYING STORMWATER PONDLIKE BMP TYPES
Wet Pond (WP) Always holds water
Extended Detention Structure Wet
(EDSW) holds permanent pool but
dewatering device next to concrete
spillway allows slow release of
floodflows
Extended Detention Structure Dry (EDSD)
retains runoff up to 72 hrs; Inside gravel
dewatering device is a perforated pipe that
slows the release of runoff from the pond
Cross-section view of typical pond
Two examples of Dry Pond (DP)
which drains very quickly once runoff
ceases
Infiltration basins
must hold runoff
until it can soak
into the sandy soils
of the basin floor
so the spillway
usually lacks an
opening until a
foot or two above
the floor.
Observation Well
Gravel trench to enhance infiltration of
runoff into underlying sandy soils
Infiltration Basin
(IB) Observation
well usually
present; holds no
water during dry
weather; gravel
trench may be
present; runoff
must pond a foot or
two before first
opening in spillway.
IDENTIFYING FILTER TYPE STORMWATER BMPS
Bioretention (BR) Micro-Bioretention (ESDMB) or Rain Garden
(ESDRG): Usually has storm drain inlet with openings one foot
above mulched or grass surface; observation well usually present.
Infiltration Trench (IT) Stone or gravel usually exposed
at surface often with observation well
Observation Wells
Swale (SW) usually has a wide bottom; observation well maybe present
Surface of Sand Filter (SF) maybe gravel
Sand Filter
Though the floor of sand filters is
supposed to be grass the sand is
frequently visible
Sand Filter (SF)
sometimes have
numerous plastic
caps present, which
may be clean-outs or
(if single) an
observation well
STORMWATER PONDS
How To Maximize Benefits for You & Your Neighbors
When properly maintained, a stormwater pond can
increase the value of nearby homes by providing an
attractive green space while serving as a community
space and wildlife viewing area. These ponds also
protect downstream property owners from flooding,
channel erosion and runoff pollution. Due to dwindling
government budgets, far too many ponds have
deteriorated. When poorly maintained, ponds can
become an eyesore, lowering property value, increasing
mosquito populations while leaving downstream
neighbors unprotected from floodwaters and other
impacts. The purpose of this fact sheet is to explain
how you can ensure that a pond remains an asset to you
and your neighbors, both next door and downstream.
STORMWATER POND BASICS
The intent of stormwater ponds is to manage runoff
from homes, buildings, parking lots, streets and other
impervious surfaces. Converting a forest to homes can
increase runoff (floodwater) volume by two- or threefold. Ponds are designed to store the difference in
runoff volume then release it gradually to prevent
downstream flooding. Also, a tremendous amount of
pollution settles on rooftops and streets, then washes
downstream with each storm. Most ponds are designed
to trap a portion of this pollution, making them essential
to preserving the Chesapeake Bay and the waters nearest
your home. Most stormwater ponds belong to one of
three types (see illustrations on other side):
Wet Pond (WP): As the name implies, these ponds
retain a permanent pool of water. When well
maintained they enhance the value of nearby homes and
may support an abundance of wildlife. They are
moderately effective in retaining pollutants. But as
sediment and vegetation fills the pool, effectiveness
declines and nuisances can become more common.
Dry Pond (DP): These facilities have a large opening
on the pond bottom. They only hold water for a few
hours following major storms. Because of the bottom
opening there is no place to retain pollutants. Therefore
dry ponds provide little protection for downstream
waters. But they can be retrofitted to increase benefits.
Infiltration Basin: An Infiltration Basin (IB) resembles
a dry pond but runoff can pool to a depth of a foot or
two before it can flow out of the Basin. The stored
runoff infiltrates into the very permeable (sandy) soils
where these facilities are used. You can also tell if a
pond is an IB by the white, plastic observation well(s)
many have. When it comes to environmental protection,
this is THE most effective pond type.
GENERAL POND ASSESSMENT METHODS
Depending upon pond type, here’s what to look for.
Wet Pond Pool Volume: Over time the pool of water in
a wet pond will fill with sediment then wetland
vegetation, both of which rob pollutant storage capacity.
Using online sites such as Google Earth, compare the
open water area of the pond today with that shown on
older photos. If it looks like open water has declined by
half or more then the pond probably needs cleaning.
Infiltration Basin: Evaluating Basins can be tricky. If
you find a pond that’s dry but there’s no opening near
the bottom or observation wells are present, then it’s
probably an infiltration basin. Determine if:
• It retains water for more than 48 hours after the last
storm; if yes then it’s clogged and needs cleaning;
• Cattails or other wetland vegetation are present, then
it’s holding water because of clogging;
• Sediment has accumulated to the first spillway
opening, then the Basin needs to be cleaned.
Dam Condition: The earth dam should be free of trees
and animal (groundhog) burrows, both of which could
lead to dam failure. While viewing the dam from a
distance, the top should appear as a straight, level
surface. There should not be any low points, except for
those ponds with an emergency spillway. Other low
points may indicate settlement that could lead to dam
failure. There should not be any wet spots or wetland
vegetation growing on the dam, even at the toe.
For further detail download Auditing Stormwater Best
Management Practices in Maryland at: ceds.org/audit.
To report pond problems go to: ceds.org/bmpreport.
COMMUNITY & ENVIRONM ENTAL DEFENSE SERVICES • ceds.org/audit • 410-654-3021 • Help@ceds.org
Sideview of Pond Embankm ent
Dry Pond: Opening At Riser
Infiltration Basin: Opening
Bottom
Above Riser Bottom
Straight, Level Earth Embankm ent; No Low Spots; No Trees or Burrows on Embankm ent
Wet Pond: Full Capacity; Little Sedimentation
Wet Pond: Full of Cattails; No Storage
W et Po nd P artially F ull W ith Se dim ent-C attails
Rem aining
INFILTRATION
BASINS
Maximizing the Benefits To Your
Home & The Environment
Infiltration basins are among THE most effective
measures for keeping stormwater pollution out of
nearby waterways. Basins are usually constructed on
sandy or other permeable soils. The basin should hold
water no more than a day or two after each storm, thus
negating mosquito problems. The runoff soaks down through the permeable soils on the basin bottom. In some
basins you’ll find a gravel structure resembling an infiltration trench which enhances the movement of runoff down
through the basin floor.
As illustrated to the left, the basin concrete spillway is
usually designed with the first opening (outlet) a foot or
two above the basin floor. This allows the basin to store
about 90% of all runoff until it can soak through the
basin floor. Many infiltration basins have an observation
well or two made of white, four- to six-inch plastic pipe,
like that pictured to the right.
Observation Well
The amount of pollution washed by rain from a residential or commercial area can
be two- to twenty-times greater than that from a forest. Runoff from rooftops, streets, parking lots and other
impervious surfaces enters the basin via a system of pipes known as storm drains. As runoff percolates through the
soil underlying the infiltration basin floor 80% to 95% of the pollutants washed from streets and other impervious
surfaces are filtered out. The infiltrated water also maintains volume in wells and provides the dry-weather inflow
essential to wetlands, streams and other waters.
Over time sediment and other material can accumulate within the stone trench and on the basin floor, depleting the
area needed to store runoff until it can infiltrate underlying soil. Most basins will have a pretreatment system such
as a forebay. If it appears that more than half the forebay original volume has been lost then it needs cleaning
KEEPING INFILTRATION BASINS HEALTHY IS EASY
1.
2.
3.
If soil is exposed to erosive forces within the area draining to an infiltration trench, then the soil should be
mulched-seeded as quickly as possible and runoff diverted away from the trench in the meantime.
An infiltration basin probably needs maintenance if:
a. Cattails or other wetland vegetation are present;
b. Water remains in an observation well more than 48 hours following a storm, or
c. The basin overflows into the concrete spillway when less than an inch of rain falls in a 24-hour period.
To report a maintenance issue Google the name of your county or city and “stormwater inspection” or contact
CEDS.
COMMUNITY & ENVIRONMENTAL DEFENSE SERVICES • ceds.org/audit • 410-654-3021 • Help@ceds.org
INFILTRATION
TRENCHES
Maximizing the Benefits To Your Home
& The Environment
Infiltration trenches are among THE most effective measures
for keeping stormwater pollution out of nearby waterways.
Unlike the infiltration trench pictured to the right, most are
covered with grass and are pretty much invisible.
Side View of an Infiltration Trench
Infiltration Trench With Exposed Stone
As illustrated to the left, a trench is
excavated four feet or more into
permeable (sandy, low-clay) soils,
filled with two-inch stone, covered
with a layer of filter cloth, and a thick
growth of grass is established on the
surface. Many infiltration trenches
have an observation well or two made
of white, four- to six-inch plastic pipe,
like that pictured to the right.
Observation Well
The amount of pollution washed by rain from a residential or commercial area can be two- to twenty-times greater
than that from a forest. Runoff from rooftops, streets, parking lots and other impervious surfaces enters the trench
by either flowing into the surface of by way of a buried storm drain pipe. The air spaces within the stone reservoir
store runoff until it can soak (infiltrate) into the adjoining soils. As runoff percolates through the soil, 80% to 95%
of the pollutants washed from streets and other impervious surfaces are filtered out.
Over time sediment and other material can accumulate within the stone reservoir, depleting the area needed to store
runoff until it can infiltrate adjacent soil. For trenches receiving surface runoff, the flow of stormwater should pass
through 20 feet or so of thick grass to reduce sediment entry. Some trenches even have a sediment deposition area
known as a forebay. Most trenches are designed to treat the first inch of runoff from the rooftops, streets and other
impervious surfaces they service. The trench should drain completely within 48 hours following the end of runoff.
KEEPING INFILTRATION TRENCHES HEALTHY IS EASY
1.
2.
3.
If soil is exposed to erosive forces within the area draining to an infiltration trench, then the soil should be
mulched-seeded as quickly as possible and runoff diverted away from the trench in the meantime.
An infiltration trench probably needs maintenance if:
a. Cattails or other wetland vegetation are present;
b. Water remains in an observation well more than 48 hours following a storm, or
c. The trench overflows with runoff when less than an inch of rain falls in a 24-hour period.
To report a maintenance issue Google the name of your county or city and “stormwater inspection” or contact
CEDS.
COMMUNITY & ENVIRONM ENTAL DEFENSE SERVICES • ceds.org/audit • 410-654-3021 • Help@ceds.org
SAND FILTERS
Maximizing the Benefits To Your
Home & The Environment
As the name implies, this BMP filters pollutants as
stormwater runoff infiltrates through a two- or three-foot
layer of sand. Sand filters are moderately effective
measures for keeping stormwater pollution out of nearby
waterways. The filters are usually constructed on sandy or other permeable soils. But with an underdrain a sand filter
can be installed on any soil.
On the other side of this factsheet you’ll find a typical sand filter design from the
Maryland Stormwater Design Manual. As shown to the left, a pit is excavated. A
gravel drainage layer is placed on the bottom. Perforated plastic pipe are then placed
on the gravel. More gravel is added to cover the pipes. This is then covered with
two- or three-feet of sand. The filter should hold water no more than a day or two
after each storm, thus negating mosquito problems.
A distinctive feature of
sand filters are the
numerous white PVC caps usually present, some of
which may be observation wells or cleanouts.
The amount of pollution washed by rain from a
residential or commercial area can be two- to twentytimes greater than that from a forest. Runoff from
Numerous white PVC caps are frequently present in a sand filter
rooftops, streets, parking lots and other impervious
surfaces flows onto the surface of the sand filter via a system of pipes known as storm drains. As runoff percolates
through the sand 40% to 80% of the pollutants washed from streets and other impervious surfaces are filtered out.
The infiltrated water also maintains volume in wells and provides the dry-weather inflow essential to wetlands,
streams and other waters.
Over time sediment and other material can accumulate on the sand filter surface which can deplete the area needed
to store runoff or the sediment can cause the filter surface to clog. Most sand filters will have a pretreatment system
such as a forebay. If it appears that more than half the forebay original volume has been lost then it needs cleaning
KEEPING SAND FILTERS HEALTHY IS EASY
1. If soil is exposed to erosive forces within the area draining to a sand filter, then the soil should be mulchedseeded as quickly as possible and runoff diverted away from the trench in the meantime.
2. A sand filter probably needs maintenance if:
a. Cattails or other wetland vegetation are present;
b. Water remains in an observation well more than 48 hours following a storm, or
c. The filter overflows at the spillway when less than an inch of rain falls in a 24-hour period.
3. To report a maintenance issue Google the name of your county or city and “stormwater inspection” or contact
CEDS.
COMMUNITY & ENVIRONMENTAL DEFENSE SERVICES • ceds.org/audit • 410-654-3021 • Help@ceds.org
Chapter 3. Performance Criteria for Urban BMP Design ......... Stormwater Filtering Systems
F-1
Figure 3.12 Example of Surface Sand Filter
BYPASS
F-1
UNDERDRAIN COLLECTION
SYSTEM
FILTER BED
FLOW DIVERSION
OUTFLOW
OVERFLOW
SPILLWAY
PRETREATMENT
SEDIMENTATION
CHAMBER
PLAN VIEW
PERFORATED
STANDPIPE
OVERFLOW SPILLWAY
FILTER BED
INFLOW
PRETREATMENT
OUTFLOW
UNDERDRAIN COLLECTION SYSTEM
PROFILE
3” TOPSOIL
18” CLEAN WASHED
“CONCRETE” SAND
GEOTEXTILE
ALL SIDES, TOP & BOTTOM
6” PERFORATED PIPE/GRAVEL
UNDERDRAIN SYSTEM
TYPICAL SECTION
Surface sand filters can treat the largest drainage area of all the filtering systems.
3.32
RAIN GARDENS & OTHER
BIORETENTION FACILITIES
Maximizing the Benefits To Your
Home, Health & Environment
A well maintained, attractively landscaped Rain
Garden enhances the value of nearby homes, makes for
a much more pleasant neighborhood, and is extremely
effective in protecting the health of local waters. In
contrast, a poorly maintained Rain Garden can become
a mosquito breeding ground full of trash and dead
plants which lowers property value. This factsheet
explains how you can ensure that a Rain Garden
remains an asset to your home and the environment.
Rain Garden In Front Of A Home
Rain Gardens, also known as bioretention facilities, are designed to treat runoff from homes and other buildings,
driveways, sidewalks, streets, parking lots and other impervious surfaces. You’d be amazed by the amount of
pollution settling from the atmosphere onto these surfaces. More pollution comes from other sources: vehicle
exhaust and engine leakage, lawn equipment, pet waste, and lawn-care chemicals drifting onto the surfaces. The
pollutant level in rainwater runoff from these surfaces can be so high that fish would die if it were used to fill an
aquarium. Rain Gardens are among THE most effective measures for preventing runoff pollution.
Rain Gardens are created by locating a point where runoff from impervious surfaces collects. A pit three- to fourfeet deep is then excavated at this runoff collection point (see illustration on other side). Most of the pit is filled
with a sandy planting soil much like that used in any other garden. Flowering plants, shrubs, and other attractive
vegetation are established within the Rain Garden then two- to three-inches of mulch is placed upon the surface.
The surface of a Rain Garden is depressed six- to twelve-inches below adjacent areas. This six- to twelve inch
depression is extremely important since it serves to store runoff for the six hours or so it takes for the runoff to soak
into the mulch layer and down through the underlying planting soil. As impervious surface runoff passes through
these layers up to 95% of the pollutants are removed. The water flowing from the bottom of the Rain Garden is
extremely clean. Since every home is within a 15-minute walk of some waterway, our children benefit through
cleaner streams in which to play, our drinking water is more healthful, and our beaches, rivers, lakes, and bays are
more enjoyable for swimming, fishing, and boating.
KEEPING A RAIN GARDEN HEALTHY IS EASY
1. Is there a depth of at least 6-inches from the Rain Garden surface to the first point where runoff could flow from
the facility? If no then the facility must be cleaned to restore a minimum 6- to 12-inch storage depth.
2. Replace any dead or dying plants. A list of suitable plants can be found in Rain Gardens Across Maryland,
available online at: http://extension.umd.edu/sites/default/files/_docs/articles/Rain_Gardens_Across_MD.pdf
3. Remove trash washed or blown into the Rain Garden.
4. If underlying soil is visible then cover the soil with mulch using well aged (6- to 12-month old) shredded or
chipped hardwood mulch.
5. Watch for indications of clogging such as water standing in the Rain Garden when a day or more has passed
since the last storm ended. If clogging does occur then see Rain Gardens Across Maryland for advice.
COMMUNITY & ENVIRONMENTAL DEFENSE SERVICES • ceds.org/audit • 410-654-3021 • Help@ceds.org
DOES RUNOFF FROM YOUR HOME, SCHOOL OR PLACE OF
WORK BENEFIT FROM STORMWATER BMP TREATMENT?
About a third of all homes, schools and businesses
drain to ponds and other stormwater Best Management
Practices (BMPs). These BMPs can trap large amounts
of pollution, making the difference between waters
suited or unfit for childhood play and a Chesapeake Bay
that is recovering or dying. In this factsheet we’ll show
you how to determine if BMPs are present and, if so,
how to tell if they are still working. We’ll also explain
how to get BMPs installed if none are present or
improve upon existing BMPs.
Impacts of Untreated Runoff
Stormwater runoff washes a tremendous amount of
pollution from lawns, streets, sidewalks, rooftops and
parking lots. Street gutters and storm drains ensure that
this highly-contaminated runoff quickly enters a nearby
waterway. The sediment, nutrients, toxics and other
runoff-entrained pollutants can do serious harm to fish
and other aquatic organisms while causing nuisances
such as excessive algae growth. The sheer volume of
runoff will erode stream channels and flood areas
never inundated prior to development.
Poorly treated suburban-urban runoff accounts for a
third to half of the most serious pollutants entering the
Bay and her tributaries. This runoff has severely
degraded the quality of the Chesapeake more than
10,000 miles of Bay tributaries from New York to
Virginia and from Delaware to West Virginia. Chances
are the waters nearest your home are among those
polluted by stormwater runoff.
Are BMPs Present?
Most existing Bay watershed BMPs are ponds, but only
a third of these hold water all the time. Photos of
common BMPs appear on the other side of this
factsheet. The newest development projects may have
small BMPs at the end of roof downspouts in the form
of stone-filled pits (dry wells) or landscaped
depressions (rain garden, bioretention). So, begin your
search for BMPs at the end of a roof downspout and
follow the path that runoff would travel. Of course,
finding this path is easiest during when runoff is
flowing. You’ll be looking for any human-made
structure that stores runoff.
Since most BMPs are ponds you’re likely to find the
structure at the end of the storm drain system. To get
there follow runoff from the downspout, across a lawn,
into a street, to the point where it drops into a storm
drain inlet. The underground path of the storm drain
system is frequently marked by manhole covers with
words like “Storm Drain” or “Storm Sewer.” Follow
manhole covers downhill looking for a low spot where
the storm drain system veers off towards a stream. The
storm drain system ends at the outfall where an open
pipe discharges runoff. Look around for a pond.
Is the BMP Working Properly?
Accompanying the photos on the other side of this
factsheet is a brief description of the more common
BMP problem indicators. Further detail is provided in
the following factsheets:
Ponds: ceds.org/audit/FS-Ponds.pdf
Infiltration Trench: ceds.org/audit/FS-Infiltration.pdf
Rain Gardens: ceds.org/audit/FS-RainGarden.pdf
Additional advice for finding BMPs, assessing their
condition and getting ailing facilities fixed, is provided
in Auditing Chesapeake Bay Watershed Stormwater
Best Management Practices:
ceds.org/audit/ChesaBaySWMBMPAudit.pdf
BMP Retrofits For A Home, School or Business
If your home, school or business lacks stormwater
BMPs, then consider a retrofit project. One of the best
How-To guides is the Community-Based Restoration
Project Manual published by the Chesapeake Bay Trust
(cbtrust.org). The Trust also offers grants to help
defray the cost of some projects. Additionally, a
growing number of local governments and watershed
groups offer retrofit assistance.
Ponds and other, older BMPs only trap a third to half of
stormwater pollutants, whereas retrofit measures can
retain 70% to 90%. So consider retrofits even if older
BMPs are present.
Finally contact CEDS if you’d like to schedule a
workshop in your area on maximizing BMP benefits.
COMMUNITY & ENVIRONM ENTAL DEFENSE SERVICES • ceds.org/audit • 410-654-3021 • Help@ceds.org
Pond must be cleaned to original capacity when
Sideview of Pond Embankm ent
half- full of sedimen t, cattails or other plan ts
Top of p on d e m ba nk m en t s ho uld be stra ig ht an d le ve l; No lo w sp ot s; No tr ee s o r a nimal burrows
Rain Garden In Front Of A Home
Is there at least 6 inches of surface storage with 2-3 inches
of woo d m ulch? Is w etland ve getation a bsent?
Bioretention
Min imu m 6 inch es s torag e, 2-3 in che s m ulch; m ust d rain
in 48 hrs; w etland plan ts indicate p oor draina ge, failure
Infiltration trench with exposed
stone; mus t drain in 48 hrs
BIRD RIVER STORMWATER BMP CHECKLIST
ID:
Site Name:
Date:
Evaluated By:
BMP Type Code: From listing:
Photos Taken:
Actual BMP type:
Location accurate: G Yes G No If no, give GPS reading: W
(see codes bottom next page)
N
Or describe location:
APPEARANCE
1. During the growing season, is the facility free of dead, dying or invasive vegetation? G Yes G Somewhat
G No
2. Is the facility free of trash or other debris? G Yes G Somewhat G No
3. Do you find the facility attractively landscaped? G Yes G Somewhat G No
FACILITY DRAINAGE AREA
4. Is the facility and the area draining to the facility free of soil erosion? G Yes G No G Uncertain
If no or uncertain, describe:
5. Can runoff clearly flow into the facility from rooftops, streets, parking lots or other impervious surfaces?
G Yes G No G Uncertain If no or uncertain, describe:
PRETREATMENT
6. Pretreatment present: G Yes G No G Uncertain
If yes, what type: G Forebay G Filter Strip G Gravel Diaphragm Other:
Does the measure need cleaning; Is sediment getting through to the BMP? G Yes G No G Uncertain
POND
7. G Pond looks good; no problems
G No wet storage
G More than half of original pool surface area
lost due to vegetation encroachment, sediment, etc.
Embankment has: G Trees G Wet Areas G Low
Spot G Animal Burrows Other:
G Pond overflowed due to less than one inch of
rain
INFILTRATION TRENCH
8. G Trench looks good; no problems
G Water visible in stone more than two days
after runoff ended
G Wetland vegetation present
G Trench overflowed from less than one inch of
rain
G Surface appears clogged with sediment
Observation Well Present: G Yes G No
BIRD RIVER RESTORATION CAMPAIGN • (410) 335-8915 • restorebirdriver.org • kavakava1216@msn.com
INFILTRATION BASIN
9. G Basin looks good; no problems
G Water present on basin floor more than two
days after runoff ends
G Grass needs maintenance; grass not thick on basin
floor; soil visible through grass on basin floor
G Wetland vegetation present
G Basin overflowed due to less than one inch of
rain
Observation Well Present: G Yes G No
If embankment pond are any of the following present on the embankment: G Trees G Wet Areas
G Low Spot G Animal Burrows Other:
BIORETENTION, MICRO-BIORETENTION, RAIN GARDEN, SWALES, etc
9. G Facility in good condition; no problems
G Water present on surface more than two days
after runoff ends
G Wetland vegetation present
G BMP overflowed due to less than one inch of rain
G Underlying soil visible; mulch-grass needs
maintenance
Observation Well Present: G Yes G No
SAND FILTER
10. G Facility in good condition; no problems
G Not draining within 48 hours after runoff ends
G Wetland vegetation present
G BMP overflowed due to less than one inch of rain
G Underlying soil visible; mulch/grass needs
maintenance
Observation Well Present: G Yes G No
OTHER BMP TYPEs
11. BMP Type:
Condition:
COMMENTS & OTHER ITEMS NOTED
BMP CODES: BR Bioretention; DP Dry Pond; DW Dry Well; ED Extended Detention; EDSD Extended
Detention Structure Dry; EDSW Extended Detention Structure Wet; ESD Environment Site Design; ESDEF
Enhanced Filters; ESDMB Micro-Bioretention; ESDRH Rainwater Harvesting; ESDSW Swale; IB Infiltration
Basin; IT Infiltration Trench; LS Level Spreader; OGS Oil-Grit Separator; PP Porous Pavement; SC
Stormceptor; SF Sand Filter; SM Shallow March; SW Swale; UGS Underground storage; WP Wet Pond