BRIEFING FOR UK & IRELAND WATER COMPANIES Welcome to a special 'CIWEM UDG 2016' issue of DHI-UK's biannual newsletter for Water Companies and their Consultants. The full and complete fourth edition will be available soon. Publication is primarily through Linkedin, so please share with your colleagues and friends.

1. ©DHI
LATEST NEWS
DHI AND BARTHAUER ENTER OEM
AGREEMENT
Expanding upon recent collaboration, DHI and
Barthauer Software GmbH have signed an
OEM agreement embedding DHI's latest
MIKE 1D engine for open and closed channel
flow into Barthauer's BaSYS software, an
information system for subsurface
infrastructure.
This agreement enables Barthauer to offer its
state-of-the-art software solutions in the field
of network management with a similarly
advanced software component for hydraulic
solutions. With worldwide network of offices,
DHI will also market this joint solution globally.
Please contact mri@dhigroup.com for more
information.
BRIEFING FOR UK & IRELAND WATER COMPANIES
Bathing Water Quality Modelling, Forecasting & Warning - Special UDG Edition
MIKE POWERED BY DHI: EMBEDDING KNOWLEDGE IN TECHNOLOGY
#4 / NOV2016 / UDG
Bathing water quality is one of the success stories of EU water policy and is
important for the protection of human health and the environment. The UK has
a large number of designated Bathing Waters governed by EU legislation and
maintaining the water quality at these sites can be a complex task. Storm
events, in particular, can lead to increased discharges into the local water
environment and these can have unwanted impacts on water quality at the
bathing beaches. Water companies, as operators of emergency outfalls, and
local groups responsible for beach management, need to be able to provide
sufficient warning to beach users to avoid public health issues and any
potential subsequent impacts on the local economy.
On the 6th and 7th October 2016, at our head office in Southampton, DHI Water
Environments UK Ltd successfully hosted a workshop on Bathing Water Quality
Forecasting and Early Warning Systems. This well attended workshop was
attended by representatives from the following consultants, water companies,
regulators and other stakeholders, as well as DHI experts from around the world.
Following introductory discussions on the current legislative framework and
guidelines, the floor was opened to allow participants (notably the Environment
Agency, Northumbrian Water, Yorkshire Water and Intertek) to share their own
recent experiences of bathing water quality monitoring, modelling, forecasting and
dissemination tools and techniques.
The participants enjoyed a dynamic and stimulating review of current local (UK
specific) and global best practice methods, examining the advantages and
disadvantage of simple, statistical, deterministic and combined systems from
around the world, before receiving detailed instruction in how to implement state-of-
the-art bathing water quality modelling, real-time forecasting and early warning
systems using MIKE OPERATIONS supported by physically based hydrodynamic
and ecological numerical models.
A follow-up workshop is planned for October 2017, please contact
sjf@dhigroup.com for more information.
iSTOCK10737976©JohnAAnderson
 Environment Agency
 SEPA
 Anglian Water
 Irish Water
 Northumbrian Water
 Southern Water
 Yorkshire Water
 AECOM
 Arcadis
 Atkins
 Intertek
 RPS
 Torbay Council
URBAN DRAINAGE GROUP AUTUMN
CONFERENCE AND EXHIBITION 2016
DHI Water Environments UK Ltd are very
pleased to again sponsor the CIWEM
Urban Drainage Group Autumn Conference
& Exhibition held over 9th - 11th November
2016 in Blackpool.

2. 2
Bathing Water Quality Modelling, Real-Time Forecasting
and Early Warning Systems
QUANTIFICATION OF SOURCES OF POLLUTION
MANAGING EXPECTATIONS
Legislative requirements and public perception of bathing
waters have changed, and the EU Bathing Water directive has
placed additional requirements on utilities in respect of CSO
discharges. With existing aging pipe networks, and
increasingly frequent intense rainfall events, managing CSO
discharges in the bathing water season continues to be
challenging. An increased focus on diffuse sources of pollution
will increase the complexity of managing bathing waters.
BEST PRACTICE
Bathing water forecasting systems are generally characterised
into 4 main types:
Systems based upon simple rules and measurements are
cheap, relatively fast and easy to use but can be too simplistic
resulting in overly conservative or even misleading
assessments. Such systems lack temporal and spatial detail
and many only consider E. coli.
Statistical systems, such as the Environment Agency’s
present bathing water forecast which simply correlates water
quality with rainfall only (linear regression), can also be
relatively inexpensive, easy to understand, adaptable, fast and
can operate at an acceptable level of accuracy (in that they
are statistically robust and, hence, difficult to challenge).
However, such statistical methods are not universally
applicable. In particular, those systems based upon a simple
linear regression of one variable (for example, rainfall) may be
appropriate for many bathing water sites but not all.
Applicability may be expanded by employing multiple
regression techniques of several variable (for example,
rainfall, tides, wind and UV) but many of the same
disadvantages of simple rule and measurement systems still
apply (for example, these systems still provide only point
based rather than spatially varying outputs).
Software tools for statistical methods are generally hard coded
‘black box’ solutions, developed for in-house use by various
organisations. Accordingly, adaptations can take time to
implement.
It is important to note that deterministic systems require
accurate estimates of pollutant loads from all sources.
Physically based dynamic models are only as accurate as the
input data but they do offer many advantages:
Combined, or multiple tier, statistical and deterministic
systems can utilise the best of both worlds. Statistical systems
can provide high and intermediate level screening of bathing
water sites (using simple linear and multiple regression
techniques respectively), meaning that physically based
numerical models can be included in forecasting systems only
where needed.
DHI has designed and installed numerous such forecasting
systems around the world. Please contact us if you would like
further information.
MIKE POWERED BY DHI: EMBEDDING KNOWLEDGE IN TECHNOLOGY©DHI
1. Based on simple rules and/or measurements
2. Purely statistical systems
3. Purely deterministic systems
4. Combination of statistical and deterministic systems
(multiple tier approaches)
Point source pollution from:
 Waste Water Treat-
ment Plant (WWTP)
 By-pass
 CSO
 Storm Water Drainage
 Misconnections
Diffuse Source pollution:
 Inland point sources
 Surface run-off
(highways, etc)
 Diffuse loads
(agricultural, etc)
DHI Water Environments (UK) Ltd
Ocean Village Innovation Centre
Ocean Way, Southampton
SO14 3JZ
Tel: +44 (0)2380 381961
mike.uk@dhigroup.com
www.mikepoweredbydhi.com
 Evaluation of single point sources and diffuse
loadings separately to screen for the critical source of
pollution (providing an initial overview of where to
invest)
 Possibility to evaluate different remedial measures /
investment options for reduction of pollution taking
account of the actual environmental conditions
(providing a solid basis for decisions and ensuring the
most cost-effective solutions)
 Real-time online dissemination of present and future
bathing water quality (providing enhanced protection
for visitors at the entire beach and during all seasons)
 Quick and easy dissemination of bathing water quality
data (providing timely and adequate information of the
public)
 Technologies and tools that support coordinated
implementation of all water directives, in particular the
Water Framework Directive
 Sedimentary re-suspension can be included
DIFFUSE
POINT