OBJ 1.2 Flashcards
Evaluate site-specific environmental constraints
Riparian
Riparian is a term in environmental science meaning inhabiting or situated on a bank of a river or other body of water. Related terms include riparian zone, riparian rights, riparian buffer, and semi-riparian.
Radon
Radon is a naturally occurring cancer-causing soil gas. It is colorless, tasteless, and odorless. Spaces that are below grade are at higher risk for radon exposure.
Superfund
Superfund is a program of the United States federal government designed to fund cleanup of sites contaminated with hazardous waste and pollutants.
Brownfield
Land that is known or suspected to be contaminated with pollutants. Examples include both former industrial sites and gas stations.
Greenfield
Land that has never been built upon.
Alluvium
A deposit of sand, mud, etc. formed by flowing water.
Loam
A rich, friable soil containing a relatively equal mixture of sand and silt and a somewhat smaller proportion of clay.
Humus
The dark organic material in soils, produced by the decomposition of vegetable or animal matter and essential to the fertility of the earth.
Lead
Lead is an element that was commonly used in certain building materials, such as paint and piping, especially in buildings constructed before the 1980s. Lead-based paint, one of the most common causes of lead poisoning, was banned from use by the federal government in 1978. Care must be taken to mitigate instances of lead during the renovation of buildings constructed earlier.
Floodplain
The floodplain is an area of land adjacent to a stream or river, beginning at the banks and ending at enclosing valley walls. (This can be a gradual sloping up or abrupt change in topography.) This lower-lying area is prone to flooding in heavy rainfalls, and building is discouraged within a floodplain.
Soil Problems in Construction
Low bearing capacity, settlement, differential settlement, expansive soils, slippage, shrinkage, heaving, groundwater, soil moisture, poor drainage, organic material, and seismic.
TDR
TDR stands for transfer of development rights. It allows land owners to sell their development rights to others who can then use them to increase development rights such as density on another site.
Acid Rain
Precipitation that contains sulfuric or nitric acid collected from the air. Acid rain is harmful to aquatic life and has a corrosive effect on many building materials, particularly metal and stone.
Catch Basin
Collects surface run-off and passes it to the storm drainage system.
Hard Water
As water filters down through the ground, it dissolves minerals, making the water “hard.” It is not hazardous but can cause deposits in plumbing pipes and water heaters.
Backdrafting (HVAC)
When combustion gases from a furnace, water heater, or similar do not exhaust properly and get into the building. It can cause death.
Turbidity
A measure of water quality that measures the amount of visually apparent suspended particulate such as sand and microbes in the water.
________ is the cloudiness of water caused by a large number of extremely fine particles. A measurement of this is a key test in water quality.
Turbidity.
Coagulation
Aluminum or other chemicals are added to water to get particles to stick together in water treatment in order to be filtered out.
Constructed Wetland
Man-made wetlands designed to provide the same qualities as their natural counterparts.
Point Source Pollution
Pollution from a single source, such as a factory or chemical spill.
Dioxins
Highly toxic and persistent (meaning they don’t break down) environmental pollutants. They are mostly by-products of industrial processes.
TDR
Transfer of development rights. Allows landowners to sell their development rights to others, who can then use them to increase development rights such as density on another site.
Acid Rain
Precipitation that contains sulfuric or nitric acid collected from the air. Acid rain is harmful to aquatic life and has a corrosive effect on many building materials, particularly metal and stone.
Sludge
The solid portions of sanitary sewer waste is held in an anaerobic (no oxygen) digester where bacteria feed on it. The resulting material is called sludge.
Clay
Determined by the size of particles and composition, clays are chemically different from their parent materials as a result of weathering. Inorganic with grain sizes of less than .0002 inches in diameter. Clay contains charged particles, has an affinity for water, and exhibits cohesion and plasticity. Makes satisfactory bearing material under some conditions. Long-term settlement will control allowable bearing pressure.
Silt
Consists of inorganic particles between .003 and .0002 inches in diameter. These fine-grained particles are similar in composition to the rocks from which they are derived and are not plastic in nature. Found at the bottom of lakes and river deltas.
Sand
Varying from fine to course, these rock particles range in size from .003 to .079 inches in diameter. Adequately compacted, sand is an ideal bearing material. The coarser it is, the higher the allowable bearing pressures. Settlement is usually immediate, with little long-term settlement.
Gravel
Classifications of gravel vary from fine to coarse, and these unconsolidated rock fragments range from .75 to about 3 inches. Except for shale composites, this is a good foundation material with very high bearing pressures by some building codes.
Cobbles
Ranging in size from 3 to 10 inches, these rock fragments can make a reliable foundation-bearing material but can be difficult to properly compact when used for fill. Cobble-sized materials can interfere with pile driving and drilled-pier construction, causing significant problems.
Boulders
Typically classified as rock fragments larger than 10 inches across , these can be used as part of a fill mass if the voids between them are filled with finer-grained sands and silts. These materials are generally not considered suitable for direct foundation support because of their size and shape and the difficulty of excavating the material to desired shapes. Can cause significant problems in construction.
Bedrock
Unbroken hard rock that is not over any other material. Depending upon its composition, bedrock can be capable of withstanding extremely high bearing pressure and is desirable for foundations supporting high loads. If weathered or cracked, the bearing capacity might be compromised. Settlement of buildings on bedrock is primarily limited to elastic settlement of the foundation.
Residuum
Consists of soil derived from the in-place decomposition of bedrock materials. These soils are more weathered near the surface and gradually transition to a more rocklike material with depth.
Colluvial Soils
Because materials are transported by gravity, these soils are generally irregular in composition and loose. They are typically associated with landslides. They require improvement prior to being used to support buildings and pavements.
Aeolian Soils
These soils are transported and deposited by the wind. Typically, they consist of silt- or sand-type soils.
Till
Mixture of clay, silt, sand, gravel, and boulders deposited by glaciers. Well-graded consolidated tills are exceptionally strong and make excellent foundation strata.
Cohesionless Soils
These types of soils consist of cobbles, gravels, sands, and non-plastic silts. They are generally formed from the mechanical weathering of bedrock brought about by water, ice, heat, and cold. Typically composed of the same materials as the parent rock. Strength is derived from interparticle friction.