Green-Field † land not previously built upon. Usually
part of the `green†belt' surrounding urban areas, designated inappropriate for
development in order to preserve the countryside. Limited development for
agricultural purposes only may be permitted on `green-belt' land.
Brown-Field † derelict land formerly a developed site
and usually associated with previous construction of industrial buildings. UK
government has set an objective to build 60% of the 4 million new homes
required by 2016 on these sites.
Site Survey † essential that a geo†technical survey
is undertaken to determine whether contaminants are in the soil and ground
water. Of particular concern are: acids, salts, heavy metals, cyanides and coal
tars, in addition to organic materials which decompose to form the highly
explosive gas, methane.
Analysis of the soil will determine a `trigger threshold
value', above which it will be declared sensitive to the end user. For example,
a domestic garden or children's play area will have a low value relative to
land designated for a commercial car park.
Site Preparation † when building on sites previously
infilled with uncontaminated material, a reinforced raft type foundation may be
adequate for light structures. Larger buildings will justify soil consolidation
and compaction processes to improve the bearing capacity. Remedial measures for
subsoils containing chemicals or other contaminants are varied.
Legislation † the Environment Protection Act of 1990
attempted to enforce responsibility on local authorities to compile a register
of all potentially contaminated land. This proved unrealistic and too costly
due to inherent complexities.
0 comments:
Post a Comment