333 research outputs found
Baseline groundwater chemistry: the Corallian of the Vale of Pickering, Yorkshire
This report describes the regional geochemistry of the groundwater from the Corallian aquifer in
the Vale of Pickering, North Yorkshire. The study aims to assess the likely natural baseline
chemistry of the groundwater. Data have been collected from strategic sampling of 24
groundwater sources, in conjunction with collation of existing groundwater, rainfall, and
mineralogical data.
The Corallian aquifer comprise Upper Jurassic shallow shelf marine sediments, with a variety of
facies including muds to micritic limestone and oolites, to bioclastic limestones with interbeds of
silts and sands. These strata represent an important groundwater source in north-east England.
The main chemical properties of the groundwater are determined by the interaction of rainwater
recharge reacting with the aquifer minerals. Within the Corallian aquifer, groundwater major ion
composition is dominantly influenced by reaction with calcite, and little variation is seen within
the major ion proportions.
Human impacts on the water quality are clearly evident, mainly through the presence of NO3-N
as an indicator contaminant. The widespread presence, commonly in excess of the drinking water
limit and the increases over time suggest that the aquifer is heavily influenced by agricultural
practices. Agricultural land dominates the area underlain by the unconfined aquifer.
With the exception of NO3-N, the available data for groundwater within the Corallian aquifer of
the Vale of Pickering indicate they are of good quality for the analytes tested, with few elevated
concentrations of potentially harmful trace elements. For many analytes the 95th percentile serves
as a first approximation of the upper limit of the baseline range of concentrations, as this serves
to eliminate the most extreme outlier concentrations
Stem cell factor (SCF) and c-kit in the ovine fetal testis in normal and nutrition perturbed pregnancies
Stem cell factor (SCF) and c-kit in the ovine fetal testis in normal and nutrition perturbed pregnancie
Risk maps for evaluation of water-quality monitoring requirements in England & Wales
This report details the steps taken in the process of producing risk (hazard) maps for chemical
parameters listed in the European Commission Directive 98/83/EC on the quality of water intended
for human consumption and the national Water Supply (Water Quality) Regulations that
implement the requirements of the directive for drinking water in England and Wales.
Amendments to 98/83/EC set out in Directive 2015/1787 provide the terms for reduced monitoring
requirements by European Member States for drinking water where evidence indicates that waterquality risk is low. On the basis of the Water Safety Plan approach of the World Health
Organization, DWI requires mapping of available data on raw-water sources in England and Wales
to provide an evaluation of spatial distributions of the listed chemical parameters and their
concentration ranges as evidence of risk for drinking water. An evaluation of temporal variability
was also required to assess evidence for any trends to aid with decision making on future drinkingwater monitoring requirements.
Data for an agreed list of 27 chemical parameters were collated, screened, evaluated and mapped,
with surface water and groundwater being treated separately. This report details the data sources
and steps taken to collate, evaluate, process and map them.
Risk maps produced for individual parameters include expected values and 95th percentiles of
measured values relative to the prescribed concentration or value (PCV) at any given location. The
methodology employed required prediction of the entire statistical distribution of each parameter
at each prediction location so that both expected value and percentile values for each parameter
could be determined. This required the use of a statistical model to represent the variation of the
data. The produced risk maps are produced for water-quality data analysed over the last three
years, in line with the requirements of the 2015/1787 Directive. The correspondence between the
two layers is an indication of the spatial data availability and the strength of correlation between
measurements from nearby sites. The maps are presented in ArcGIS with additional explanatory
layers comprising open-source data for coastline, multiscaled atlases, postcode sectors, place
names, simplified geology, Environment Agency region boundaries and local authority boundaries
as points of reference. The GIS is presented as a separate mxd file.
The maps have inevitable limitations derived from inability to guarantee complete elimination of
errors from the cleaned datasets, paucity of data for some parameters, spatial and temporal
variability of available data for others, variable spreads of surface-water drainage or aquifers,
variable detection limits for some trace elements, and for groundwaters, variable chemistry with
depth, especially for concealed and/or stacked aquifers. Nonetheless, the maps provide an estimate
of the current best-available spatial distributions for parameters for surface water and groundwater
to aid DWI in assessing drinking-water risks and determining monitoring requirements, in line
with Directive 2015/1787. It is anticipated that the maps will be used alongside available sitespecific water-quality monitoring data and site risk assessments for decision making in the context
of the Directive.
Temporal variability of raw water chemical data have also been assessed. As temporal trends vary
significantly spatially for individual parameters and between parameters, recommendations for
timescales of map revision are difficult to make. As a pragmatic recommendation, a mapping
renewal interval on the order of 10 years is considered appropriate. In the case of amendments to
the statutory PCVs in the meantime, remapping is possible using the existing rasters and relating
to the revised threshold values
The General Solution of Bianchi Type Vacuum Cosmology
The theory of symmetries of systems of coupled, ordinary differential
equations (ODE) is used to develop a concise algorithm in order to obtain the
entire space of solutions to vacuum Bianchi Einstein Field Equations (EFEs).
The symmetries used are the well known automorphisms of the Lie algebra for the
corresponding isometry group of each Bianchi Type, as well as the scaling and
the time re-parametrization symmetry. The application of the method to Type
VII_h results in (a) obtaining the general solution of Type VII_0 with the aid
of the third Painlev\'{e} transcendental (b) obtaining the general solution of
Type with the aid of the sixth Painlev\'{e} transcendental (c) the
recovery of all known solutions (six in total) without a prior assumption of
any extra symmetry (d) The discovery of a new solution (the line element given
in closed form) with a G_3 isometry group acting on T_3, i.e. on time-like
hyper-surfaces, along with the emergence of the line element describing the
flat vacuum Type VII_0 Bianchi Cosmology.Comment: latex2e source file, 27 pages, 2 tables, no fiure
Impacts on groundwater quality from abandoned hydrocarbon wells - final report
This report details a reconnaissance investigation carried out between 2016 and 2018 from a British
Geological Survey (BGS)–Environment Agency (EA) collaboration on the impacts of abandoned
hydrocarbon (HC) wells on groundwater quality in England. The investigation involved collation of a
database of HC wells that were identified from records provided by DECC (Department of Energy &
Climate Change; now BEIS: Business, Energy & Industrial Strategy) as being abandoned (as opposed
to operational or unspecified), categorising according to factors such as oil or gas designation, depth of
HC resource, time since abandonment, productive life, absence of active wells nearby, and occurrence
and type of overlying aquifer(s). From this categorisation, a subset of 27 sites were shortlisted for further
investigation and fact sheets were produced for each outlining regional geology, hydrogeology and
potential groundwater monitoring points in the area. Using these factsheets, four study areas were
assessed as being most suitable for further field investigation. These comprised two gas fields: Nooks
Farm (Staffordshire), and Ashdown (Sussex), and two oil fields: Hemswell (Lincolnshire) and Lomer
(Hampshire).
Groundwater sampling campaigns were conducted in 2016–2017 in the four study areas, with potential
sampling points identified within a 5 km buffer zone around (downstream of) the HC well or HC field.
In several areas, the number of sampling points was very limited as locations of HC wells do not
necessarily have any relationship with locations of overlying aquifers. In others, large numbers of sites
were deemed unsuitable for sampling, for reasons including disuse, decommissioning, safety or lack of
access. This made representative sampling of groundwater a severe challenge. Suitable sites from the
four study areas were sampled twice during the project, with a total of 48 groundwater samples being
collected over the two campaigns.
Results from both sampling rounds have shown that the presence of hydrocarbons in the groundwater
is limited. In the first sampling round, a maximum dissolved methane (CH4) concentration of 407 μg/L
was recorded. However, this relatively high value was not repeated when the site was visited during the
second round of groundwater sampling. The value was below the threshold required for δ13CCH4 isotopic
analysis. Some groundwater samples showed detectable quantities of organic compounds including
VOCs (volatile organic compounds) and PAHs (polycyclic aromatic hydrocarbons) as well as
pesticides, herbicides, fungicides, surfactants, analgesics and veterinary compounds. These were,
however, almost invariably present in low concentrations, none could be linked unequivocally to the
presence of abandoned HC wells and many were clearly due to other anthropogenic activities.
As a result of the difficulties finding representative and suitable groundwater sampling sites, a further
reconnaissance was undertaken in May 2017 to identify potential alternative gas and oil fields. This
confirmed further the difficulties in finding suitable areas for investigating groundwater quality and
further groundwater sampling was therefore not attempted. An alternative approach was used to
investigate two abandoned HC well areas: Ashdown, one of the original study areas, and a new location
at Bolney (also Sussex). A soil gas survey was completed at each of these locations in order to
investigate whether soil gas proximal to the former well location contained any evidence of HC leakage.
Due to poor ground conditions at the time of sampling, the results are ambiguous, but do show elevated
concentrations of both CO2 and CH4. Further work in dry ground conditions would be required to say
with certainty that these concentrations are linked directly to the presence of the gas wells
Trade-offs constrain the success of glyphosate-free farming
Glyphosate, the most widely used herbicide, is linked with environmental harm and there is a drive to replace it in agricultural systems. We model the impacts of discontinuing glyphosate use and replacing it with cultural control methods. We simulate winter wheat arable systems reliant on glyphosate and typical in northwest Europe. Removing glyphosate was projected to increase weed abundance, herbicide risk to the environment, and arable plant diversity and decrease food production. Weed communities with evolved resistance to non-glyphosate herbicides were not projected to be disproportionately affected by removing glyphosate, despite the lack of alternative herbicidal control options. Crop rotations with more spring cereals or grass leys for weed control increased arable plant diversity. Stale seedbed techniques such as delayed drilling and choosing ploughing instead of minimum tillage had varying effects on weed abundance, food production, and profitability. Ploughing was the most effective alternative to glyphosate for long-term weed control while maintaining production and profit. Our findings emphasize the need for careful consideration of trade-offs arising in scenarios where glyphosate is removed. Integrated Weed Management (IWM) with more use of cultural control methods offers the potential to reduce chemical use but is sensitive to seasonal variability and can incur negative environmental and economic impacts
Nonlinear Differential Equations Satisfied by Certain Classical Modular Forms
A unified treatment is given of low-weight modular forms on \Gamma_0(N),
N=2,3,4, that have Eisenstein series representations. For each N, certain
weight-1 forms are shown to satisfy a coupled system of nonlinear differential
equations, which yields a single nonlinear third-order equation, called a
generalized Chazy equation. As byproducts, a table of divisor function and
theta identities is generated by means of q-expansions, and a transformation
law under \Gamma_0(4) for the second complete elliptic integral is derived.
More generally, it is shown how Picard-Fuchs equations of triangle subgroups of
PSL(2,R) which are hypergeometric equations, yield systems of nonlinear
equations for weight-1 forms, and generalized Chazy equations. Each triangle
group commensurable with \Gamma(1) is treated.Comment: 40 pages, final version, accepted by Manuscripta Mathematic
Effect of extended cefquinome treatment on clinical persistence or recurrence of environmental clinical mastitis
The effectiveness of antibiotic treatment of clinical mastitis (CM) is classically evaluated using bacteriological cure, which provides a concise and objective way of assessing efficacy but does not reflect the situation in the field where persistence or recurrence of clinical signs lead to perceived treatment failure. If clinical signs persist or recur, intramammary (IMM) treatment is often extended or supplemented with parenteral therapy in the expectation of a more efficient elimination of clinical signs or a lower probability of recurrence.
The objective of this study was to evaluate the efficacy against clinical persistence or recurrence of three cefquinome treatment regimes, standard 1.5-day intramammary (SIMM), 5-day extended intramammary (EIMM) and combination of EIMM plus 5-day extended parenteral (ECOMBO) treatment. The study was conducted on three dairy farms with a high recurrence rate of environmental mastitis. Efficacy was evaluated using a multi-level model at the quarter and at the cow level, based on the persistence or recurrence of clinical signs at any time during a 105-day period following the end of the initial treatment, independent of pathogen.
The most prevalent pathogens were E. coli (16.9%) and S. uberis (11.97%). EIMM and ECOMBO significantly decreased the persistence or recurrence of CM by 8% and 6% at the quarter level and by 9% and 8% at the cow level, respectively. ECOMBO may not reduce the persistence or recurrence of CM beyond EIMM. Whilst extended treatment regimens offered an improved outcome in this study, the producer and practitioner need to carefully consider such regimens from the perspective of prudent antibiotic use
Preliminary assessment of the environmental baseline in the Fylde, Lancashire
This report presents the collated preliminary results from the British Geological Survey (BGS) led project Science-based environmental baseline monitoring associated with shale gas development in the Fylde, Lancashire. The project has been funded by a combination of BGS National Capability funding, in-kind contributions from project partners and a grant awarded by the Department of Business Energy and Investment Strategy (BEIS). It complements an on-going project, in which similar activities are being carried out, in the Vale of Pickering, North Yorkshire. Further information on the projects can be found on the BGS website: www.bgs.ac.uk.
The project has initiated a wide-ranging environmental baseline monitoring programme that includes water quality (groundwater and surface water), seismicity, ground motion, atmospheric composition (greenhouse gases and air quality), soil gas and radon in air (indoors and outdoors). The motivation behind the project(s) was to establish independent monitoring in the area around the proposed shale gas hydraulic fracturing sites in the Fylde, Lancashire (Cuadrilla Resources Ltd) before any shale gas operations take place.
As part of the project, instrumentation has been deployed to measure, in real-time or near real-time, a range of environmental variables (water quality, seismicity, atmospheric composition). These data are being displayed on the project’s web site (www.bgs.ac.uk/lancashire). Additional survey, sampling and monitoring has also been carried out through a co-ordinated programme of fieldwork and laboratory analysis, which has included installation of new monitoring infrastructure, to allow compilation of one of the most comprehensive environmental datasets in the UK.
The monitoring programme is continuing. However, there are already some very important findings emerging from the limited datasets which should be taken into account when developing future monitoring strategy, policy and regulation. The information is not only relevant to Lancashire but will be applicable more widely in the UK and internationally. Although shale gas operations in other parts of the world are well-established, there is a paucity of good baseline data and effective guidance on monitoring. The project will also allow the experience gained, and the scientifically-robust findings to be used, to develop and establish effective environmental monitoring strategies for shale gas and similar industrial activities
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