Figure 1. The rate of
accidents involving heavy trucks in counties in Pennsylvania with 20 or more
wells operating before 2012, the rate for those counties with less than 20
wells, and the number of well pads drilled, using Pennsylvania Crash Reporting
System data. (Resources for the Future report, September 2014).
Traffic...
It takes lorries to develop a shale gas pad – lots of lorries
and other vehicles. They are needed to prepare the site, construct the rig,
carry the drilling string and casing, import the drilling and fracking fluids,
export the flow-back fluid, carry drilling staff, inspectors, managers and
scientific monitoring teams, take down the rig and sometimes to export the
produced gas. If there are protests, there is also an increase in protestors'
traffic, and the consequent traffic associated with policing and security.
Balcombe
How much
traffic was a question that was asked by the Parish of Balcombe when test
drilling was proposed there in 2013. The Balcombe Parish Council produced a
very reasonable and readable report that touches on every aspect of the
proposed drilling. Its section on traffic states that they were expecting seven
to eleven weeks of activity with the largest vehicles being expected at the
start and the end of that period, associated with the construction and taking
down of the rig. They expected 10 Heavy Goods Vehicles (HGVs) per day for the
majority of the period and 30 HGVs per day for the most active two weeks at
each end of the drilling. The light vehicle traffic was also expected to
increase by 30 vehicles per day.
How does
that compare with the background traffic through Balcombe? Well, of the 10,000
vehicles per day that have been measured to pass through Balcombe in several
recent surveys, 4000 use the road that was to be used for the drilling traffic,
and of those 200 were HGVs. That implies an increase of 15% in the HGV traffic
for the busiest 2 weeks, 5% for the remaining 5 to 9 weeks, and less than 1%
for the light vehicles.
In practice,
it did not work out quite as it was planned. Local figures indicate that
fracking protests delayed and obstructed HGV traffic sufficiently to ensure
that many lorries took two or more attempts to access the site, while the
estimated 5000 fracking protestors' cars and vans increased the light vehicle
traffic by over 50% compared to the background level on some days; an irony
given that no fracking was even planned at the site.
The Balcombe
experience is just an interesting story; the development of a fully-fracked 40
lateral pad such as that which would be used in full scale shale gas
exploitation is a different kettle of fish. What would be the traffic required
for that?
Likely UK Scenario
The
Institute of Directors have used data from high quality sources, mainly provided
by the European Union, to estimate the number of lorry movements associated
with shale gas production. They estimate that a single 10-well pad of 40 laterals could see 11,155-31,288 truck movements over 20
years, depending on whether the
water comes from a mains connection or is brought in
by road. Assuming truck movements
are
concentrated in the early years of drilling activity, this averages out at
6.1-17.1 per day over
five years. This number accords well with
the Cuadrilla/Balcombe Parish Council figure of about 20 per day, but over a
shorter period (6 weeks) for the Balcombe case because they were envisaging one
well with one lateral.
Spilt Milk!
It is
worth putting this
number of lorry and tanker
movements into context. British dairy farmers produce 11 million m3 of milk each year.
Milk tankers vary in size, but assuming a tanker capacity of 30 m3, 366,667 milk tanker
journeys would be needed each year in rural locations to transport milk from the farms where it
is produced. Consequently, if you are not inconvenienced
by milk tankers, it is unlikely that you will be inconvenienced by the
development of the 400 lateral per year annual development , which is the
likely size of a maturing UK shale gas industry.
US Shale Gas Road Fatalities
On
balance, therefore, it would seem that the increase in traffic caused by shale
gas development would be significant, when considered from the point of view of
the number of extra vehicle journeys to be undertaken, but insignificant when
put in the context of all the other journeys that happen on our roads every day
as a matter of course. However, there is one very important piece of
information that we have not yet considered. The largest loss of life
associated with shale gas developments worldwide (mostly in the USA) is from
road traffic accidents; accidents which often involve large tankers using roads
that were not designed for them and local rural traffic that had hitherto had
the lanes to themselves (Figure 1). Fault does not always lie with the shale gas traffic
either, but the sharing of small, rural roads does lead to loss of life.
Although the number is still small, and much smaller than the loss of life from
coal-generated air pollution,
each loss is significant for those involved.
Resources
for the Future (RFF) is a voluntary funded organisation in the USA which was
involved in developing environmental economics over 60 years ago. It provides
high-quality objective research and analysis on critical issues such as energy,
climate, ecological quality, and forest management. Resources for the Future
published a report in September 2013 which examined the impact of heavy goods
vehicles on the safety of roads in those areas where shale gas exploitation was
being carried out in Pennsylvania using that state’s Crash Reporting System
(CRS). They compared the rate of accidents involving heavy trucks in counties
with 20 or more wells operating before 2012 to the rate for those counties with
less than 20 wells, and compared both to the number of well pads drilled. The
result is shown in Figure1 above. It is clear
that the increase in the accident rate for counties with greater than 20 wells
compared to those with less than 20 wells after 2009 when they had been
approximately the same at earlier dates correlates strongly with the post-2009
increase in well pad drilling. In fact the increase in traffic accidents
involving heavy goods vehicles is 2% for every new well drilled per month.
