Appendix 2: Water quality in the Bradford Beck and tributaries Contents Aims and scope................................................................................................................................................................... 3 Background ......................................................................................................................................................................... 3 Catchment description .................................................................................................................................................... 3 Official water quality information ..................................................................................................................................... 4 River quality condition, up to 2009 ............................................................................................................................. 4 Water Framework Directive, 2009 onwards................................................................................................................ 5 Historical data on organic chemicals .......................................................................................................................... 5 Incidents and anecdotes ................................................................................................................................................. 6 2009 fish kill................................................................................................................................................................ 6 Ambler Mill.................................................................................................................................................................. 6 2012 diesel spill .......................................................................................................................................................... 6 Malfunctioning CSOs .................................................................................................................................................. 6 Construction activity, September 2012 ....................................................................................................................... 7 Previous studies of water quality .................................................................................................................................... 8 British Geological Survey ........................................................................................................................................... 8 Centre for Ecology and Hydrology.............................................................................................................................. 8 Urban Pollution Modelling for Yorkshire Water ........................................................................................................... 8 2012 sampling and interpretation ........................................................................................................................................ 8 Basis of a sampling campaign ........................................................................................................................................ 8 Volunteers....................................................................................................................................................................... 9 Locations ........................................................................................................................................................................ 9 Sampling and analysis methods ................................................................................................................................... 10 Results .......................................................................................................................................................................... 11 BOD.......................................................................................................................................................................... 11 Phosphorus .............................................................................................................................................................. 11 Ammonia .................................................................................................................................................................. 11 Metals ....................................................................................................................................................................... 12 Organic chemicals .................................................................................................................................................... 12 Chloride and boron ................................................................................................................................................... 12
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Appendix 2: Water quality in the Bradford Beck and tributaries€¦ · status are shown in Table 2 together with the results for the Beck. It is classified as good chemical quality
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Appendix 2: Water quality in the Bradford Beck and tributaries
Contents Aims and scope ................................................................................................................................................................... 3
Official water quality information ..................................................................................................................................... 4
River quality condition, up to 2009 ............................................................................................................................. 4
Water Framework Directive, 2009 onwards................................................................................................................ 5
Historical data on organic chemicals .......................................................................................................................... 5
Incidents and anecdotes ................................................................................................................................................. 6
2009 fish kill ................................................................................................................................................................ 6
Construction activity, September 2012 ....................................................................................................................... 7
Previous studies of water quality .................................................................................................................................... 8
British Geological Survey ........................................................................................................................................... 8
Centre for Ecology and Hydrology .............................................................................................................................. 8
Urban Pollution Modelling for Yorkshire Water ........................................................................................................... 8
2012 sampling and interpretation ........................................................................................................................................ 8
Basis of a sampling campaign ........................................................................................................................................ 8
BOD .......................................................................................................................................................................... 11
Chloride and boron ................................................................................................................................................... 12
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Conclusions and recommendations .................................................................................................................................. 14
Annex A: Summary of historical data on organic chemicals.............................................................................................. 15
Annex B. Average concentrations observed in Bradford Beck ......................................................................................... 19
Annex C Summary of organic chemical analyses, November 2012 .................................................................................. 22
Tentative positives and negatives ............................................................................................................................ 22
Figure 1 Schematic map of the Bradford Beck catchment .................................................................................................. 3
Figure 2 Distribution of historical landfills in the Bradford Beck catchment (from the Environment Agency website) ......... 4
Figure 3 Culvert exit at Amber Mill (picture from http://multi-story-shipley.co.uk/?m=201203) .......................................... 6
Figure 4 Intermittent foul discharge from CSO, Pitty Beck, November 2011 ...................................................................... 7
Figure 5 Sewage discharging from a CSO in Shipley in dry weather du`e to a sewer blockage, July 2012........................ 7
Figure 6 Sediment pollution of the Beck near Shipley from a construction site about 5km upstream, September 2012 ..... 8
Figure 7 Water quality sampling points ............................................................................................................................. 10
Figure 8 Longitudinal profile of chloride concentrations along Pinch and Bradford Becks ................................................ 13
Figure 9 Boron vs phosphate concentrations for all samples ............................................................................................ 14
Table 1 Summary of chemistry General Quality Assessment results for Bradford Beck at Shipley (from Environment
Table 2 Current ecological and chemical status (from Environment Agency website, November 2012) ............................ 5
Table 3 Summary of water quality sampling undertaken .................................................................................................... 9
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Aims and scope
The Bradford Beck was classified by the Environment Agency as of poor ecological quality in 2009 for the purposes of
the Water Framework Directive. This study aims to update this classification and determine the nature and sources of
pollution in the Bradford Beck and its tributaries. The interpretation was based on multiple rounds of water samples from
19 locations taken by volunteers during 2012.
Background
Catchment description
The Bradford Beck catchment of about 60 km2 in area is illustrated in Figure 1. The Beck rises in the west and relatively
rural area of the catchment (Pitty and Pinch Becks). Through much of the urban area, it flows in culvert, with very few
stretches open to the atmosphere. All the tributaries in the urban area are also culverted (Westbrook, Bowling Beck and
Eastbrook), with most of them running through industrial areas. After the Beck emerges from the culvert, it is canalised
all the way down to its confluence with the River Aire in Shipley; some stretches are also culverted.
In the early 1990s, a flood diversion tunnel was constructed (Figure 1). This can take water from Westbrook and the
Bradford Beck upstream of the city centre and rejoin the Beck downstream, reducing the risk of flooding in the city
centre. In dry weather there should be no flow in the diversion but this was not the case during the period of this study
2012 when significant flows went through the tunnel.
Most of Bradford is on a combined sewer system (i.e. foul and storm water in the same pipes). There are 51 CSOs
(combined sewer overflows) in the catchment, through which excess flows are discharged to surface water during wet
weather. In the early 2000s, 10 storm tanks were installed to store and reduce the frequency and size of such spills, but
Figure 1 Schematic map of the Bradford Beck catchment
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spills have not been eliminated. In addition, there are an unknown number of outfalls for surface water; these are
unregulated and may have foul water drains misconnected to them.
Much of the land alongside the becks has been filled in order to raise levels and create flat areas of land for construction,
often of industrial sites. Other land has been used as landfill (Figure 2). There is a high likelihood that much of these
infilled areas will be contaminated land and at risk of leaching pollution into the streams.
Figure 2 Distribution of historical landfills in the Bradford Beck catchment (from the Environment Agency website)
Official water quality information
River quality condition, up to 2009
The GQA (General Quality Assessment) scheme was used to assess and report river water quality from 1990 to 2009.
Rivers were graded from A (very good) to F(bad) each year for chemistry, biology and nutrients. The chemistry CGA
used measurements of ammonia and dissolved oxygen to grade rivers. Table 1 gives a selection of the results for the
Bradford Beck at Shipley and shows that there have been significant improvements since 1990. The GQA score has
gone from E in the early 1990s to A or B by the late 2000. The major change around 1994 coincides with the closure or
reduction in size of a particular processing plant. In 2009, the method of classifying water quality changed with the
introduction of the Water Framework Directive.
Table 1 Summary of chemistry General Quality Assessment results for Bradford Beck at Shipley (from Environment agency website)
Overall physico chemical quality Moderate Moderate ammonia Ammonia Moderate Dissolved Oxygen High pH High Phosphate Good
Overall specific pollutants quality Moderate Moderate ammonia and cypermethrin Ammonia Moderate Arsenic High Copper High Cypermethrin Moderate Iron High Permethrin High Zinc High
Chemical status, composed of: Good Overall priority substances Good All good
Aldrin, Dieldrin, Enrin & Isodrin Good Carbon Tetrachloride Good Dichloro-Diphenyl-Trichloroethane (Para-para) Good Tetrachloroethylene Good Trichloroethylene Good
Overall priority hazardous substances Good All good 1,2-dichloroethylene Good Cadmium (and its compounds) Good Hexachlorobenzene Good Hexachlorobutadiene Good Hexachlorocyclohexane Good Lead (and its compounds) Good Nickel (and its compounds) Good Trichlorobenzenes Good Trichloromethane Good Trifluralin Good
The Environment Agency stopped monitoring water quality in Bradford Beck in 2009.
Historical data on organic chemicals
Annex A summaries the Environment Agency’s data on organic chemicals in the Beck at Shipley for the period 1984-
2010. A number of these chemicals, mainly pesticides, would have failed the Environmental Water Quality standards
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under the EU Priority Substances Directive. However, Annex A shows that concentrations have been falling over the
years and are no longer of major concern, provided there are no significant spillages and incidents.
Incidents and anecdotes A number of pollution incidents have been recorded in the last few years. Although we do not have a complete list of
these, some examples are given below which show that significant pollution incidents have occurred and are detrimental
to chemical and ecological quality.
2009 fish kill
In May 2009, over 1000 trout and
numerous other fish were found dead in
the Bradford Beck. The incident was
investigated by the Environment Agency.
It was ascribed to a chemical release from
industrial premises in Bradford, but the
actual source was not found and no
further action was taken.
Ambler Mill
Ambler Mill sits over the downstream end
of the 2.5 km culvert that carries the
Bradford Beck through Bradford (Figure
3). This reach receives the inflows from
Eastbrook and Bowling Beck. There have
been complaints from the Mill’s occupants
of bad smells emanating from the culvert.
The smell is obvious to any visitor, particularly on warm days. On the days that ART visited, it was a smell of
biodegradation of organic matter. The problem has been investigated by CBMDC, the Environment Agency and
Yorkshire Water but no specific source has been found. The smell is thought by some to be caused by sewer gas which
is the gas produced by biodegradation of sewage in the enclosed space of sewers. Normally it would vent at CSOs
which are open to the atmosphere; in this case the CSOs vent into the enclosed spaces of the various culverts upstream
of the Mill. This diagnosis has not been confirmed officially by any of the parties concerned.
2012 diesel spill
At the CBMDC depot on Shearbridge Rd, 5500 L of diesel was lost from an underground storage tank. Some of it found
its way to the Westbrook and much of the rest infiltrated into the ground and is the subject of a current clean-up
operation.
Malfunctioning CSOs
In November 2011, an ART catchment walker observed a CSO in Pitty Beck which was intermittently discharging foul
water (Figure 4 Intermittent foul discharge from CSO, Pitty Beck, November 2011). This was reported to Yorkshire
Water; we do not know if the cause was found and rectified.
In July 2012, an ART catchment walker observed a major, continuous discharge from a CSO in Shipley which polluted
an 800 m stretch to the confluence with the River Aire (Figure 5). This was reported to both Yorkshire Water and the
Environment Agency. It was apparently caused by a manhole cover blocking a sewer and the raised levels spilt through
the CSO. It took several days to clear the blockage.
Figure 3 Culvert exit at Amber Mill (picture from http://multi-story-shipley.co.uk/?m=201203)
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Figure 4 Intermittent foul discharge from CSO, Pitty Beck, November 2011
Construction activity, September 2012
In September 2012, an ART catchment walker observed significant discolouration of the Bradford Beck at Shipley
(Figure 6). This was reported to the Environment Agency which traced it to construction of an Asda supermarket on
Cemetery Road. Construction work in the Beck polluted about 5 km of the stream for several days. We understand that
legal action against the polluters is being considered.
Figure 5 Sewage discharging from a CSO in Shipley in dry weather du`e to a sewer blockage, July 2012
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Previous studies of water quality
British Geological Survey
The British Geological Survey took stream and sediment
samples in 1995 from several un-urbanised tributaries of the
Bradford Beck as part of their geochemical mapping of the UK
(http://www.bgs.ac.uk/gbase/). We have used these analyses as
a check on our own.
Centre for Ecology and Hydrology
The Centre for Ecology and Hydrology used the Bradford Beck
for a research project under the URGENT programme of
research on urban impacts. Rainfall, river flow and suspended
sediment concentrations were monitored at several locations
from 1999 to 2001. Several research papers were published1
related to the production and modelling of suspended sediment
in urban areas. One paper showed that winter gritting of roads lead to significant increases in specific conductance of
the river water, showing that there is a direct connection between road drainage and the river, even without large rainfall
events to trigger CSOs.
Urban Pollution Modelling for Yorkshire Water
As part of the design of engineering works to improve “unsatisfactory Intermittent Discharges” to Bradford Beck, a
computer model was constructed of the sewer network and its discharges, and used to explore design options. A paper
which summarises the work was presented to the WaPUG meeting in March 2004; unfortunately it contains very little
data or model results on water quality before and after the construction of the measures2.
2012 sampling and interpretation
Basis of a sampling campaign The Environment Agency’s water quality sampling stopped in 2009 and was mainly designed to classify the waterbody.
To update the information on water quality, diagnose why the ecological quality is poor and to identify the sources of
pollution, new and more detailed spatial information is required. In addition, the previous sampling did not routinely
include the full range of organic chemicals that may be present. Therefore, sampling throughout the catchment was
conducted (19 regular locations, 3 one-off locations). To ensure that the interpretation was not distorted by single
anomalous results, samples were taken on several occasions (maximum of 7). Each set of samples was taken at
approximately the same time to get snapshots in time of the water quality throughout the catchment.
1 Old et al., The impact of a convectional summer rainfall event on river flow and fine sediment transport in a highly
urbanised catchment: Bradford, West Yorkshire. The Science of the Total Environment 314 –316 (2003) 495–512
Goodwin et al., The temporal and spatial variability of sediment transport and yields within the Bradford Beck catchment, West Yorkshire. The Science of the Total Environment 314 –316 (2003) 475–494.
Old et al., River flow and associated transport of sediments and solutes through a highly urbanised catchment, Bradford, West Yorkshire. The Science of the Total Environment 360 (2006) 98-108.
Old et al., Physical and chemical extremes of the urban river environment: Bradford Beck, UK. Hydrology: Science and Practice for the 21st Century, British Hydrological Society (2004), 318-325
2 Caudwell, Bradford UPM – Modelling the Change. WaPUG Spring Meeting (2004) 5 pages.
Figure 6 Sediment pollution of the Beck near Shipley from a construction site about 5km upstream, September 2012
Annex C Summary of organic chemical analyses, November 2012
The results of organic analysis are shown in Table C1 at the end of this Annex. Where compounds were detected but
were below quantification level, <0.10µg/l has been recorded. Where compounds were not detected (which could mean
concentrations below 0.020µg/l for some compounds), N.D. has been recorded.
Points of note:
Priority substance tetrachloroethylene (widely used in dry cleaning and degreasing) was detected in three of the
samples. Due to the volatile nature of this compound, a quantitative value has not been quoted. The calculated
values of around 0.2µg/l are significantly below the AA-EQS (10µg/l) and no tetrachloroethylene was detected
in the Shipley site sample. This compound is detectable in the water at three sites nearly five years on from
previous analysis. Future work could include VOC analysis to quantify what is present and map concentrations
across the city as an indicator of pollution sources.
Trace levels of PAHs (acenaphthene, phenanthrene, fluoranthene, pyrene) were found in nearly all the
samples, consistent with general city pollution. The priority hazardous substance anthracene was not detected,
however the priority substance fluoranthene was detected in all but one of the samples and this PAH serves as
an indicator of the presence of more hazardous PAHs. Those higher molecular weight compounds are likely to
be bound to sediment due to their poor solubility in water.
The priority substance naphthalene was detected at four sites, the highest concentration being at Shipley
(0.28µg/l) which is the most downstream site. This is still below the AA-EQS of 2.4µg/l.
Many substituted benzenes were detected at trace levels, especially in the Shipley sample. 1,2,4-
trimethylbenzene (added to and present naturally in fuel) was detected in all samples, highest in Shipley at
0.23µg/l. This was not analysed for in the EA data.
Trichlorobenzenes (TCBs) were not detected, supporting EA data that showed a decrease to undetectable
levels. These had previously been present at levels that would have led to failure of the water body.
Tentative positives and negatives
Tentative reprocessing of the data can be achieved by looking for ions of interest determined from library data at the
retention times indicated by the NLS method (after correction for our system). This enabled us to tentatively analyse for
many more compounds than we have available in standards, down to comparable detection limits. Three separate
methods were used; one for the WFD Annex X list of priority substances, one for selected pesticides and one for
‘interesting’ compounds (substances of abuse, sewage indicator compounds etc).
Reprocessing using these methods gave three tentative positives out of approximately 80 compounds. Traces of priority
substance atrazine and its breakdown product atrazine desethyl were found in Site 10 (Eastbrook). The AA-EQS for
atrazine is 0.6µg/l, likely well above the detected level. Traces of metaldehyde were found in Sites 09 (Westholme St)
and 13 (Cemetery Rd), and a larger amount in Site 10 (Eastbrook). Metaldehyde (used in slug pellets) is a widely
occurring pollutant.
An interesting finding in the organic analysis was the presence of caffeine in all the samples. Caffeine can be used as an
indicator of infiltration of sewage into the river system which will most likely be through misconnections. The data show
an increase in concentration measured going into the city from the west (Site 13 to Site 9) with similar levels through the
city going north. The highest concentration was at Eastbrook (Site 10), which has been shown from the inorganic data to
be among the most polluted sites. However, the data cannot conclusively determine any relationship between the sites
without measuring flow: the flow at Eastbrook is much less than at other sites, therefore there could be a lower mass
flow of caffeine through that site or even pollution local to that site may not be diluted to the extent it is at other sites.
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Further work on the concentrations of caffeine in samples taken from more sites along with flow data on sampling could
have the potential to highlight misconnections in the city and act as a general indicator of river contamination.
Table C2 Caffeine concentrations relative to the highest observed value
Site Normalised response
(Eastbrook = 100%)
Site 01 - Shipley 18.4%
Site 03 - Poplar Rd 26.7%
Site 07 - Ambler Mill 23.7%
Site 09 - Westholme St 18.1%
Site 10 - Eastbrook 100.0%
Site 13 - Cemetery Rd 7.3%
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Table C1 Results of organic analysis of samples taken 8th November 2012. Yellow and red highlights refer respectively to priority and priority hazardous substances under the Water