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Tiêu đề Property and Area Reconnaissance
Trường học Unknown Institution
Chuyên ngành Environmental Site Assessment
Thể loại Chapter
Năm xuất bản 2008
Định dạng
Số trang 30
Dung lượng 5,69 MB

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When it is not feasible to investigate every foot of a property, minimum coverage should include the following: Around the perimeter of the property All surface water routes, including d

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A site and area reconnaissance is performed to observe existing conditions

and activities These conditions and activities may or may not have been pre‑

viously identified through other means If they are not previously identified,

the investigator attempts to find potential sources of environmental contamina‑

tion not previously encountered and evaluate possible means by which the

soil and water may become contaminated Sometimes a site visit will confirm

suspicions At other times, it will open new avenues for further investigation

Although the process may appear to be quite straightforward, such an

attitude can result in oversights Some environmental professionals like to

use a checklist One must keep in mind, however, that checklists can be lim‑

iting, and they often require illogical observations (e.g., conditions of ponds

in a rural environment)

A site inspection requires common sense, an analytical mind, and persis‑

tence If something appears out of place, it probably is An old dirt road over‑

grown with vegetation has a reason for being, and it should be questioned

Although many of these issues are discussed within this chapter, the realm

of possibilities is limited only by one’s imagination Published recommenda‑

tions and mandates can be limited in scope, but the environmental profes‑

sional should not limit the scope

The ASTM Standard recommends a visual inspection of the subject prop‑

erty, with no specific requirement to inspect adjoining properties with the

exception of noting anything actually observed from the subject property

The Rule requires a visual inspection of the subject property and adjoining

properties If, however, for some reason a visual inspection cannot be per‑

formed, the environmental professional should perform one of, or a combi‑

nation of, the following:

Visually inspect the subject property via another method (e.g., obser‑

vations by air) or from an alternate vantage point (e.g., walk the prop‑

erty line)

Document efforts taken to gain access to the subject property

Document the use of other sources of information to determine the

existence of potential environmental contamination

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Express an opinion about the significance of the failure to conduct a site

inspection on the ability of the environmental professional to identify

conditions indicative of releases or threatened releases

The discussions within this chapter go beyond what is recommended by

ASTM or mandated by the All Appropriate Inquiries Rule It is up to the

environmental professional to limit or extend the search

Reconnaissance of the Property

A site reconnaissance is a thorough investigation of the grounds and all

ing buildings, which may be accomplished during the grounds inspection

All activities performed in and around the buildings have an impact on the

property, and the property may have had other uses than were derived from

Plan the visit The site investigator may require special equipment For

instance, an eight‑hour walk‑through of a densely vegetated, 200‑acre lot, on

a hot, humid day may require a machete, lightweight and heavy duty boots,

a long‑sleeved shirt, a water jug, a backpack, and some form of self‑defense

(e.g., mace) along with paper, writing implements, and a camera If planning

to collect samples, take the necessary equipment Think in terms of accessi‑

bility, consolidation of supplies, and reduced bodily discomforts

Area diagrams are a must They include a copy of the plat and area map

Plan on getting them dirty, marking them up extensively (e.g., locating

55‑gallon drums), and taking extensive notes (See Figure 7.1.)

Too many or a lack of proper supplies can result in extended reconnais‑

sance time Taking too much can cause a logistics juggling act Taking too

little may necessitate an additional trip to retrieve needed items and can be

time consuming

Always carry a clipboard and writing implements Notes will get wet

and dirty Use permanent markers or pencils that will not bleed, resulting in

unreadable information

Prior to departing for the site, review collected information Take notes

during the planning stages for the site reconnaissance and generate ques‑

tions The review should include, but not be limited to, the following:

Environmental setting

Historic usage of the property

Building records

Regulatory agency listings

The investigator should attempt a visual evaluation of every square foot of

the property, but it is not always feasible to walk an entire area To overstate

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Property and Area Reconnaissance 3

the obvious, a flat, barren 1‑acre plot of land is easier and less time consum‑

ing than a 1,000‑acre parcel of property with gullies and thick vegetation

When it is not feasible to investigate every foot of a property, minimum

coverage should include the following:

Around the perimeter of the property

All surface water routes, including dry creek beds

All roads, paved and unpaved

All areas that are reasonably accessible

Figure 7.1  Search of property Notes taken during site reconnaissance for signs of

environmental conditions that may have a negative impact on the property.

north

prevailing winds low tr affic

15 deg ree slo

pe of land cyclone fence @ per imeter

patch of dead veget ation

metal build

ing patche s in concrete

possib le evidence of under ground storag e

tain.) hard packed soi

l, weeds , native grasse s

nd

distre ssed veget ation

8’ out from build ing

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Some of the more common techniques used to ensure adequate coverage

of “accessible land” include the following:

Parallel coverage—Property can be walked in parallel patterns, with

5‑ to 20‑foot separations from the center The distance from each cen‑

terline should depend on the ground visibility

Expanding circles/squares—Property can be walked by starting at the

center and walking outward in a methodical fashion This may involve

a walk around a high point or an accessible portion Property with a

central focal point (e.g., a hill) with a shape conducive to this approach

is the most likely candidate for this technique

Last, prior to departure to the site, contact the people designated as the

contact for the property They will want to be kept informed if the investiga‑

tor is not to be escorted, and they will require notification if the investigator

needs an escort

Once on site, the investigator must be aware of all possibilities and then

some The succeeding items are those most frequently included on an item‑

ized checklist, along with a few other considerations generally overlooked

or ignored

Topographic Conditions

The topographic conditions of the site and surrounding areas should be

observed and compared with the topographic maps for the area These will

most likely be similar, but topographic maps are not updated frequently A

comparative analysis will disclose outdated maps

Dated information becomes highly important, especially where there

is the likelihood for migration of hazardous substances and/or petroleum

products through the soil or into surface water and groundwater In some

instances, the city may have recently contracted for planimetric ground con‑

touring of the area Planimetric maps are typically more detailed than topo‑

graphic maps and generally more dated

General Description of Structures, Roads, and Fences

All structures and other improvements or usage passageways should

be described and identified on a schematic of the property The size and

number of buildings should be estimated (and confirmed later) along with

approximate construction date, number of stories, and probable usage (See

Figure 7.2.)

Dirt roads, foot paths, streets, and parking facilities provide information

as to type, volume, and pathways of travel Fences and walls confine areas

that may have had a designed purpose and subsequent use Each item should

be identified on the schematic

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Property and Area Reconnaissance 

Inside Structural Observations

Whether a building is complete or only partial, an effort should be made

to observe in‑structure impact components that may be indicators of envi‑

ronmental contamination This should include, but not be limited to, the

following:

Means of heating and cooling (e.g., gas, oil, or electric): If gas or oil were

used, you should locate the storage tank/container

Stains and corrosion: If stains and/or corrosion are observed, you

should question the source or cause

Drains and sumps: If there are floor drains and/or sumps (i.e., a pit

for draining, collecting, or storing liquids), you need to question their

intent and use

Although an industrial building generally poses a greater concern than a

residence, illegal dumping and illegal drug labs do occasionally occur in

residences Signs and symptoms of environmental contamination in any

structure should result in further investigation at a later date

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Especially in rural environments, waste is managed by some form of ground

waste management system, whether it is conventional leaching fields, leach‑

ing chambers, or aerobic systems Many of today’s waste disposal systems

are engineered, but the older systems may have been installed in ground

that allows the wastewater to percolate down to the subsurface water table

(e.g., aquifer) or run off into surface water (e.g., streams) Some structures,

past and present, are built on the cheap, with a big hole in the ground, not

unlike an outhouse without a collection system The environmental profes‑

sional should determine, by records or interviews, the age and type of sys‑

tem installed—if one was installed

Sanitary Sewers

The location of all sanitary sewers should be noted One should also iden‑

tify the drain locations, because sanitary sewer water typically does not get

treated while being emptied into a river, stream, or creek beds These are

paths whereby runoff of surface water containing hazardous substances and

petroleum products may depart the property

The river, stream, or creek bed into which the sanitary sewer water emp‑

ties may be on the property or on environmentally sensitive adjoining prop‑

erties For this reason, the destination of associated sewer water should also

be determined

Water Wells

Today, the installation of water wells is a controlled process Twenty years

ago, it was not Now, the well‑drilling operator is required by law to cement

the surface casing and/or cement intervals where inter‑aquifer transfer may

occur The intent is to prevent travel of soil contaminants from one segre‑

gated geologic layer to the next or to the groundwater In the past, the driller

was not required to comply with any of these procedures, thus older wells

pose a greater threat to the groundwater than those more recently installed

in accordance with acceptable practices For a rendering of a poorly installed

water well, see Figure 7.3

Abandoned wells may pose a problem as well Besides providing a hot spot

for someone to fall into, abandoned wells may serve as an easy means for ille‑

gal dumping of hazardous materials The well water may be associated with

an aquifer that is used by others who may unknowingly drink the contami‑

nated water A small community using well water may develop an increased

incidence of an exotic illness The occurrence of miscarriages and/or deformed

fetuses may increase A rare debilitating disease may affect large numbers of

a community A rare form of cancer may prevail Sometimes these latter sce‑

narios are the only reason for suspicion within a given population

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Property and Area Reconnaissance 3

There have been cases where abandoned wells doubled for a septic sys‑

tem Household waste has been innocently piped out to a big hole in the

ground Although human waste generally breaks down to a non‑hazardous

substance, there is a potential for conveyance of the parasites and bacteria in

feces Other wastes also may have been disposed of, such as household paint

products or motor oil

Some second‑world countries still have systems in which the water

wells are not encased and adequately separated from the community

septic system They have no more than a hole into which household and

septic waste is discharged Next to the waste hole is an unprotected water

rock formation

water formation

Rope and Bucket direct access to groundwater

Unprotected Surface Area

no concrete pad to protect from surface contaminants

Open Top

no protection from dumping and debris

surface soil

sand and gravel

Porous Curbing potential for subsurface contamination

Figure 7.3  Depiction of unprotected well (Source: Partial extraction from Texas

Department of Health: Individual Home Water Supplies Austin, Texas Stock No 2‑105,

Oct 1970, p 18.)

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well These countries have a lot of problems with diseases conveyed by

fecal matter

All water wells should be evaluated and the possibilities considered Fur‑

ther research may be indicated after the site visit

Drinking Water Sources and Quantity

The drinking water may come from personal water wells, cisterns, or city

supplies The city water source may be a lake, reservoir, river, or aquifer

Today, personal water wells are initially analyzed for quality, and unless

the owner is suspicious, the well may not get checked again Contamination

may occur subsequent to the initial check, but the owner or potential buyer

may not be aware of the contaminant If there is reason to be suspicious, the

investigator may collect a sample of the water and have it analyzed for the

suspect hazardous substance This may require collection of the water in a

sterile, quart‑sized, glass jar with inert sealing material Prior to collection,

information concerning the methodology for taking the sample and means

for shipping it should be confirmed with the analytical laboratory that will

perform the analysis

A cistern is a water retention device, built into the ground, for collection

and storage of bathing and/or drinking water It may be a rain collection

container at the base of a roof drain spout It may be a primitive hole in the

ground, or it may be an insulated, contained bladder built into the ground

An abandoned cistern may serve as a means for contaminant disposal, or

it may even be physically dangerous (e.g., a child could fall in) Some older

cisterns contained lead sealant, a source for lead contamination of the envi‑

ronment (See Figure 7.4.)

The city water may be on an old system, and lead solder may have been

used in some of the soldered joints where there are metal pipes, or lead pipe

may even be present The city can provide information concerning lead con‑

tent of the supply lines

The lines leading from the supply main may also have lead Lead content

in the water can be determined as per Chapter 9 If the results of a sample

from a home or other building exceed the acceptable limit of 15 ppb (parts

per billion), this should be compared with the supply line analysis performed

by the municipality

Debris

Many properties that have yet to be developed have become a convenient

dumping ground Dumping is generally in the form of household junk and

motor oil, but industrial dumping may occur as well

Domestic dumping may include old tires, auto parts or whole automobiles,

plastic jugs, paper, roofing material (possibly containing asbestos), cleaning

product containers, unused paint, and so on (See Figure 7.5.)

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Property and Area Reconnaissance 

Figure 7.4  Old cistern found around an old, vacant cabin.

Figure 7.5  Domestic debris with asbestos‑containing roof shingles.

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Industrial dumping comes in all sizes, shapes, and forms Containers gen‑

erally are not labeled and certainly are not traceable A number of scenarios

are possible As the cost of industrial disposal increases, the temptation for

illegal dumping increases

Chemical Storage Containers/Drums

Today, all chemical storage containers that are shipped directly from a manufac‑

turer or distributor must be labeled with the trade name, manufacturer, and

specific hazards associated with the chemical Labels provide information as

to chemicals used on site in a manufacturing operation Take notes, even if

there appears to be no associated problem with the containers

Sometimes a container is not labeled Labels may get damaged in ship‑

ment, worn away by weather, torn off through rough handling, or eaten away

by chemicals (e.g., sulfuric acid dripping down the side of a glass bottle)

Some of the worst hazardous waste sites within the United States contain

hundreds of thousands of such drums Many leak, and the chemicals in two

adjacent containers may not be compatible In other words, they may leak

out, mix with one another, and result in a fire or explosion, or react with one

another to produce a toxic gas Some may have a residue in the lid, around the

opening, causing an explosion when the container is opened For example,

oxidized hydrogen peroxide crystals formed in the cap of a storage container

have been known to explode simply by the friction of turning the cap

Likewise, the drum may never have had a label A chemical may have been

transferred from a marked container to an unmarked container A drum may

contain only water or it may contain explosives Unmarked drums that no one

can identify should be handled with extreme caution, and unless properly

trained to manage unknowns, the environmental professional should seek

the aid of someone experienced in management of unknown containers

Sometimes the contents of drums are known, but their whereabouts are

unknown For instance, witnesses know that several mercury‑containing

drums were buried in a field, but they do not know their exact location Steel

drums have a “maximum life expectancy” of fifty years, and locating suspected

burial sites requires speculation and extensive soil sampling (i.e., a Phase II

assessment) Some may also be detected by the use of a magnetometer

Do not be surprised to find drums in the middle of undeveloped land

After three hours walking beautiful country property you may begin to

wonder why you are spending so much time with no findings Then you bust

out into an opening and find rusting drums oozing with black goop You just

never know (See Figure 7.6.)

Soil Mounds

Backfill is identified by obvious disturbances in the surface of the soil In

a field of vegetation and/or grass, newly placed backfill will have nothing

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growing on it Within weeks, however, grass will grow and the site may be

recognizable only by the presence of a mound (See Figure 7.7.)

Containerized and non‑containerized substances may have been dumped

into a hole and backfilled The method of hole preparation and soil coverage

may be that of a modern‑day landfill, with special liners and soil‑type precau‑

tions, or it may involve a blatant disregard for the environment A chemical may

be poured into a hole of highly porous soil with no attempt to contain its spread,

or drums with a limited life expectancy may be randomly placed into a hole

Look for mounds that seem out of place For example, a 10‑foot high, 20‑foot

wide mound in the center of a flat field with no explanation or rationale for its

presence would be suspicious A mound may be nothing more than the excess

from property leveling, or it may be a small landfill of drums containing haz‑

ardous wastes The owner may be able to explain its purpose; but if there is no

rationale for its presence, a mound will require further speculation

Ground Depressions

Concave surfaces may be found over an area where the contents of a drum

have seeped into the ground and all the containers have collapsed under the

pressure of the soil or where buried debris has degraded This area may be

Figure 7.6 Deteriorated drum found in a cattle grazing pasture.

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a small, 5‑foot‑diameter depression in the soil, or it could be a hundred feet

across In the latter, it is easier to observe a depression by looking at aerial

photos than by walking the area (See Figure 7.8.)

Where obsolete underground storage tanks may collapse, asphalt/con‑

crete surface covering will cave in also There may be other signs of the exis‑

tence of such a structure, or all other evidence may have been destroyed In

the latter situation, there may be no other clue as to the presence of such a

tank, without the observed ground depression

Distressed, Stained Soil

Mishandled chemicals may result in contaminated grounds This may

involve spills, container leaks, or intentional dumping In the soil, the

contaminant may migrate into the subsurface soils, surface water, and

groundwater Some of the signs of mishandling include extreme dryness,

cracking, discoloration, a distinct wet spot next to a chemical storage

container or where one used to be, noticeable sheen, or a residue ring

These items should be noted for possible investigation at a future date

(See Figure 7.9.)

Poor or No Growth of Vegetation

Lack of vegetation in an area that is typically vegetated may indicate poi‑

soning, either from an herbicide or from contamination by a hazardous

Figure 7.7 Depiction of a soil mound concealing deteriorated drums that poten‑

tially contain hazardous chemicals.

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substance or material that will not allow growth Further investigation is

indicated (See Figure 7.10.)

Dead Wildlife

Dead animals around a water source can certainly indicate contaminated,

poisoned waters However, do not assume the water is contaminated with

chemicals The deaths may be due to disease or some other factor that may

Figure 7.8 Depiction of a ground depression with hidden, collapsed containers that

potentially contain hazardous chemicals.

Figure 7.9 Stained soil, indicating potentially hazardous chemicals leaking into

the ground.

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not be readily apparent This definitely deserves investigation (i.e., a Phase

II site assessment)

Oftentimes, fish are used in laboratories for chemical toxicity testing

because of their extreme sensitivity to toxic substances Generally, the fish

in a stream of contaminated water will die before other wildlife is affected

Check surface waters that normally contain fish Note whether the fish are

flourishing or the water is lifeless For instance, along the Gulf of Mexico, a

manufacturer was dumping heavy metal contaminants into an estuary that

was spilling into gulf waters During this time, catfish were dying and wash‑

ing up on the beach, a fish being deposited every other foot all along the

shore Catfish are bottom feeders They were poisoned by the heavy metal

that had settled to the bottom of the gulf shoreline

Consider again dead animals around a source of water If mammals are

dead but the fish are thriving, look for other potential causes If both are

dead, it is probably the water Regardless, further research is indicated

Evidence of Surface Water Contamination

Surface waters include, but are not limited to, lakes, rivers, streams, springs,

and creeks Use your senses to evaluate these—look, touch, and smell

Observe the top of the surface waters Look for floating debris and surface

sheen or a layer of apparent differentiation (e.g., a thin red layer of an uniden‑

tified muck floating on the top of the water) (See Figure 7.11.)

Excessive soil runoff into the water supplies nutrients and mud to the

water You may not be able to see any fish in such waters, yet they would

thrive quite well The use of surface water as a viable fishing hole may

provide clues as to the existence of fish Surface algae would also indicate the

probability of high nutrient levels

Fecal material may enter the surface water by a makeshift human waste

discharge It may also occur from large numbers of cattle, horses, sheep, and/

or other farm animals This waste will elevate coliform bacterial growth,

Figure 7.10 Hardened, cracking wastewater sludge taken from landfill.

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Property and Area Reconnaissance 

carry disease, and provide a breeding ground for undesirable bacteria The

odor may provide a clue

The edges of the surface water may show signs of contaminants If the

water level has recently dropped or if there is an area where the water has

been restricted from entry by a dike, the edges may be observed for deposits

An oil deposit will be black and slimy to the touch

During dry spells, creeks may not have any water Yet, in the rainy sea‑

son, the investigator should expect the creek beds to retain water, unless

there is a means for water seepage into rock formations Lack of water in a

creek during the rainy season could be significant if the water is, or becomes,

contaminated The surface water is going deeper, increasing the poten‑

tial for groundwater contamination where there is known surface water

contamination Even where the soil and rock provide a very poor means for

contaminants to travel to the groundwater and/or aquifers, fissures in the

creek bed may provide direct, easy access to a local private water well or

to a reservoir Material may also migrate by entering shallow, non‑potable

groundwater and be conveyed to other properties

Figure 7.11  Waste and debris floating in recreational surface water.

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