Catchment
Based Thinking
to Industrial
Wastewater
Treatment
By Rich Matthews, General Manager,
Siltbuster Process Solutions
A
s part of A P6 the water industry is already
taking some steps towards catchment
management. Indeed, when it comes to tackling
diffuse pollution issues, that threaten the aquatic
environment, water companies comfortably adopt such an
approach. They adeptly identify the often local, root causes
of any problems and mitigate or eliminate them accordingly.
Yet, when it comes to industrial wastewater treatment,
an area which potentially puts a greater burden on
infrastructure, this approach comes less naturally to the
sector. Instead, investment decision-making is generally
made at the end of pipe’. As a result, efficiencies are
missed and problems are not tackled at source.
There are a number of compelling reasons why this
entrenched way of operating should be over-turned and
a catchment-based approach to industrial wastewater
treatment should be considered.
Unpredictable Problems
The first has to be industrial unpredictability and risk.
It is e tremely difficult for water companies to predict
with certainty how demand from an area’s industrial and
commercial base is likely to develop and grow, or to forecast
the upside and downside of demand in a specific area.
This is a very real problem as, from an operational
perspective, apart from storm ows, it is the uctuations
in industrial contributions ows and loads that place the
greatest stress on the wastewater treatment infrastructure.
It’s not ust the treatment facility that is impacted by this;
conveyance systems are affected too by industrial demand.
Risk to Conveyance Infrastructure
A purely centralised approach, where the problem is purely
dealt with ‘at the end of the pipe’ also presents an increased
risk to conveyance infrastructure in terms of the ows and
types of e uents to be catered for. For e ample, significant
trade discharges can have high loads that can affect pump
stations and other sewerage infrastructure, leading to a
greater risk of pollution events. The control of fats, oils and
greases (FOG) is a particular focus area and contributor to
this.
o in essence water companies face a significant potential
pressure from their commercial communities, and these
communities can e and grow quite unpredictably
The use of well-managed Trade
uent Consents, and
charging by Modgen formula, provide the tools to both
control industrial discharges and implement a pricing
strategy which ensures revenue for investing in wastewater
services. However, where should that investment be best
placed?
Investing Closer to the Customer
This is where we would argue that catchment based thinking
comes into its own. SPS has undertaken a number of
pro ects with food and drinks companies seeking to improve
their discharge compliance performance and / or to reduce
their trade e uent charges. ften these systems can be
installed as relatively simple retro-fits. ome have even the
potential to provide a revenue income; e.g. feedstock for AD
plants. Dissolved Air Flotation (DAF) technology has proven
time and again to be a cost effective and robust process for
reducing organic load into the sewerage system at source;
particularly in relation to FOG applications.
As an example, the use of a DAF system complete
with packaged chemical pre-treatment facility treating
wastewater from a ready meals producer, typically achieved
an 87% reduction in TSS, and a 70% reduction in of COD.
Furthermore, since this packaged treatment system has
been installed it has treated ~120,000 m3, with a gross
saving of circa £50,000 in Mogden charges since October
2014.
However, more importantly this has significantly reduced
the demand on the existing conveyance and treatment
infrastructure
At present it is the proactiveness of industrial customers in
managing their operation and expenditure that drives this
approach. However, given the potential reduction in both
the load and the associated stresses on infrastructure, water
companies should perhaps themselves look at how some of
their assets can be better deployed by treating at source.
Of course there may be scenarios where the traditional
end of pipe solution is the right one. We also acknowledge
that the catchment approach to industrial water treatment
requires a significant shift in the water sector’s investment
model. Primarily in the operational philosophy outlook
and responsibility, by treating solutions on third party land
and the additional interfaces. However, with engineering,
construction and space constraints increasingly inhibiting
the sustainable development of wastewater treatment sites,
we really believe higher rate, smaller footprint, intensive
treatment processes, working where the problem originates
present a real answer. The change in approach will deliver
enough significant benefits to merit this shift in thinking.
For further information on Siltbuster Process Solutions,
please visit www.siltbuster.com, call 01600 772256 or
email [email protected]
Issue 20 PECM
63