By Alan Markoff, email@example.com
Tuesday 8th November, 2005 Posted: 14:54 CIT (19:54
A scarcity of high quality aggregate for road bases
and building lots will probably ease in the coming weeks as soaked quarry operations dry out, said quarry operator Buddy Wood.
However, the continuing demand for land fill to meet
development needs has the Department of Environment ready to test the environmental impact of deeper excavation of current
quarries as a medium–term strategy, and to explore the feasibility of the commercial importation of aggregate as the
Deputy managing director of the National Road Authority
Edward Howard noted recently that obtaining supplies of good land fill was a factor in estimating how far the $3 million budgeted
for the extension of the Esterley Tibbetts Highway would take the road.
“Fill is increasing in price and getting scarce,”
he said. “Everyone wants to build 10 feet above sea level because of Ivan.”
Mr. Wood, who said there was ample supply of rough
fill, admitted that the high quality, finer aggregate known as crusher run was getting scarce.
“(Crusher run) takes longer to make,” he
said, noting that when it is wet, as it has been in recent weeks, it is difficult to sift the fill.
“Once it dries out, we should catch up,”
Mr. Wood said high quality crusher run can cost as
much as $24 a cubic yard, while shot rock, a lower quality fill with larger chunks of rock, is running about $16 cubic yard
Mr. Wood said there has definitely been increased demand
since Hurricane Ivan as people try to raise the elevation of their property to avoid storm surge flooding.
“I’d say (the demand) is 35 to 40 per cent
higher,” he said.
Stanley Scott of Scott’s Equipment, which operates
another of Grand Cayman’s active quarries, thinks that figure could be even higher.
“I would say demand is getting close to 50 per
cent more since Ivan,” he said. “It’s putting pressure on all the pits.”
Adding to the demand has been the large scale development
Camana Bay, which has needed considerable land fill in its first phase.
While the immediate problem of a scarcity of good land
fill might be alleviated with drier weather, organisations like the National Roads Authority, the Department of Environment
and the Water Authority are all concerned about creating too many quarry sites on Grand Cayman.
Mr. Howard said most of Cayman’s quarries, including
inactive ones, are in the Eastern districts, and that the large numbers of quarries will make it more difficult for the placement
of future roads.
DoE assistant director Scott Slaybaugh is concerned
about how much of Grand Cayman will be sacrificed to quarries.
“We need to decrease the number of [quarry] footprints
we create,” he said.
Mr. Slaybaugh said an extensive study – called
the CH2MHill report – about managing aggregate resources to meet development needs was completed in September of 2002.
While the report was comprehensive, it did not account
for the increased demand caused by Hurricane Ivan, Mr. Slaybaugh said.
“It’s a very professional study, but it
was a bit short–sighted in that it didn’t expect the unexpected.”
It was estimated in the report that Grand Cayman had
a demand of one million cubic yards of aggregate each year. That figure has gone up since Ivan.
Mr. Slaybaugh said there is about a seven million cubic
yard reserve of aggregate on Grand Cayman.
The CH2MHill report recommended, among other things,
a pilot study to determine the environmental impacts of excavated quarries deeper than the allowed 12 to 14 feet below the
For a variety of reasons, that pilot study had been
delayed for several years.
Late last year, the Aggregate Advisory Committee, a
multi–agency governmental technical group, agreed to allow excavation of Cayman’s active quarries to a depth of
Mr. Slaybaugh said it is hoped a pilot study could
commence the early part of next year excavating three half–acre plots on one quarry to 30, 40 and 50 feet below the
surface to determine the environmental impacts.
Quarry owner Buddy Wood said he thinks the Government
should have allowed deeper excavation a long time ago.
“I’ve been saying that for years, but no
one listened,” he said. “It’s a good step. We can get more (aggregate) in a smaller area.”
Hendrik van Genderen, a water resources engineer with
the Water Authority, a member of the AAC, said there are several reasons precautions have to be taken if quarries are to be
One of the chief concerns is whether excavating quarries
deeper could possibly bring an incursion of brackish into Grand Cayman’s fresh water lenses.
The Water Authority never supports having a quarry
over a fresh water lens, but even if it is only near a fresh water lens, a quarry could have a negative impact, Mr. van Genderen
“The lenses depend on rainfall that seeps through
the rock,” he said. “When you create a (quarry) lake, you have a high amount of evaporation, so the lens could
start losing water.
Mr. van Genderen said the Water Authority generally
knows where Cayman’s fresh water lenses are, but there is a margin of error because the exact location of the lenses
can not be defined above the ground.
A quarry could also affect ground water levels on agricultural
land, Mr van Genderen said.
Another potential concern about excavating quarries
deeper is the odour.
“The deeper you go, the more you are faced with
a lack of oxygen,” Mr. van Genderen said. “When waste gets into a lake and starts to rot, it smells bad.”
Even if the pilot study shows it is safe to excavate
quarries somewhere between 30 and 50 feet deep, the CH2MHill report only recommended deeper quarries as the medium term strategy
to supplying Grand Cayman’s aggregate needs.
For the long term, the report recommended developing
the infrastructure to facilitate the large–scale importation of aggregate products.
To make it economically feasible to import aggregate,
Grand Cayman would have to construct a permanent offloading dock removed from the George Town area that would accept large
The CH2MHill report recommended a complete feasibility
evaluation to be done for such a facility by 2004, and that the facility be functional between 2007 and 2012.
Mr. Slaybaugh said that study was never done; however,
some private enterprises have expressed some interest in undertaking the project.
In the interim, Mr. Slaybaugh pointed out that there
are other ways Grand Cayman can reduce its demand for aggregate.
“We’re talking to the developers all the
time,” he said, noting that one way developers can reduce their needs for land fill is by only raising the level of
the building foundation area, rather than the whole property, to promote water drainage.
The DoE also recommends erecting buildings of the ground