Chemical dosing systems: repair or replace?

Love it or ditch it?

Let’s face facts, when equipment breaks down, the primary concern is how will productivity and profitability be impacted in both the short and long term? Not to mention the general public’s water supply being disrupted if there is downtime at the water and wastewater works.

When breakdowns occur, we go back to the age-old question of repair or replace? It is a decision that requires careful consideration in order to maintain productivity and manage costs. Corporations have long used the 50 per cent rule as a guide: if breakdowns and repairs exceed 50 per cent of the total cost of replacing equipment, then you should replace it outright.

However, in a world where repair and remanufacture promotes a circular economy and is the more sustainable option, the regular servicing and maintaining of equipment mean that those old 50 / 50 guidelines are shifting.

Systems must be maintained regularly
Reliable and efficient chemical dosing systems, for example, are vital to the regulatory compliance, safe management and cost-effectiveness of water and wastewater treatment operations. To avoid equipment failures and minimise leaks, spills and blockages, these systems must be properly and regularly maintained. However, as we’ve seen over recent years, many companies are falling short of this.

In fact, when the Environment Agency released its latest annual report on the environmental performance of England’s water and sewerage companies, it showed that four out of nine companies are falling short of expected standards, which is having a detrimental impact on the environment. Ultimately, if you are not maintaining your equipment regularly you will have no choice but to replace it and perhaps face other consequences. Not making maintenance your priority has other repercussions too:

Shortened asset life
Poorly maintained dosing equipment simply won’t last as long and a replacement will mean adding to the company’s capital expenditure (CAPEX). Most other savings achieved through maintenance relate to operating expenditure (OPEX). Considered holistically, the benefits of good servicing can be combined to enable effective planning and optimisation of total expenditure (TOTEX).

Without regular servicing and recalibration where necessary, a dosing system can end up injecting larger quantities of chemical than needed. Energy consumption may also increase when equipment isn’t functioning at full efficacy.

Environmental harm
If the doses from a failing system are too low, insufficiently treated wastewater may be discharged into the environment. If doses are too high, the discharge may be toxic. In the event of a significant chemical leakage or untreated discharge due to faulty equipment, the effects on rivers, streams and other habitats may be devastating. Along with the cost of fines, enforcement undertakings and remedial works, the company will be facing a PR disaster.

Breakdown? Have you considered hiring a chemical dosing system?
Other maintenance-related services from WES include replacing components, upgrading or re-purposing systems, relocating equipment, modifying controls and training operators.

As an alternative to replacement, we can also support operations through various other solutions. This includes the rapid delivery of hired dosing systems in emergency situations, or where planned shutdowns are scheduled.
In short, whatever a business needs to keep its chemical dosing systems well maintained, we have alternatives so that the fallback doesn’t have to be replace.

How can WES help?
Specific maintenance needs vary between sites, applications and the nature of existing equipment. We offer a free on-site survey to audit the chemical dosing system regardless of age or manufacturer, against current standards and best practice. An assessment of the equipment’s general condition is produced, along with recommendations on any repair or upgrade work needed. Based on those reports, WES will make a recommendation.

specification and installation pain points

Overcoming the pain points

specification and installation pain pointsLeonardo da Vinci, the world-renowned artist and engineer, said ‘wisdom is the daughter of experience’. So, with this in mind, here is some food for thought for those looking to overcome those all too frequent specification and installation pain points, based on the WES team’s extensive experience in this field:

Location, location, location  – with more stringent requirements for the removal of phosphorus under AMP7, there has been an increase in demand for chemical dosing systems on smaller, trickier sites. To overcome the pain point of a difficult location or small footprint, many compact packaged dosing systems are increasingly popular. This is because:

  • Compact dosing systems have an immediate flexibility advantage over their large predecessors, as they give wider scope for location choice, fitting easily into smaller sites
  • Systems like the DS1500 from WES come with inbuilt weather protection, expanding applicability to both outdoor and indoor locations
  • Self-contained small and large chemical dosing systems, such as those supplied by WES, are single lift packages that are flexible enough to meet all control requirements and other product standards relating to different water utilities and approved suppliers.

Keeping the costs down – the best way to keep costs down is to minimise any nasty surprises. This is where standardisation, experience and simplicity can make all the difference:

  • Using framework designs that are agreed upon by the supply chain can help a standardised cost to be achieved by a delivery provider
  • Experience can also help simplify the specification and reduce costs. The team at WES has been able to halve costs for some customers as they have used their skills and knowledge to provide a better design. For example WES delivered cheaper costs on a project by looking at a different way of achieving the end result, coming up with a 5m2 system compared to the original 3.5m x 7.5m solution.

Speeding up delivery times – time is money and mistakes can be costly in terms of service quality, expense and speed. To ensure the job is delivered as efficiently and cost-effectively as possible:

  • What checking process does the supplier have in place to minimise errors? At WES even the most straightforward jobs are peer reviewed by others, to make sure that no one has made a mistake that will lead to delivery delays or additional costs
  • Getting to the root of the problem not only saves time but money. A good supplier will ask questions and ideally check the site, so that the problem is understood and the right solution specified.

None of the suggestions listed here are rocket science. They are just based on the WES team’s years of experience in delivering the right chemical dosing system, in the right time frame and at the right price.

For more information on how WES can help you achieve the best chemical dosing system to meet your needs – painlessly – please contact us

Peace of mind with quick turnaround

When it comes to chemical dosing systems, more and more water and wastewater businesses are using the option of hired in services. In these difficult times, choosing a provider that can meet even unexpected demands, quickly, is essential.

The reasons businesses choose to hire chemical dosing systems are many and varied and include the need to: Hire equipment

  • Solve an emergency – when equipment suddenly stops working, a hired system keeps things going, giving time to identify the cause and carry out repairs
  • Support planned maintenance – when the original dosing system undergoes a planned shutdown for maintenance, refurbishment, upgrading or expansion, a hired solution can keep things moving
  • Test and evaluate new treatment strategies and processes – to meet more stringent regulations and reduce operating costs, hire systems enable the completion of tests and field trials to choose the best way forward
  • Meet changing needs – demand or treatment requirements are subject to changes and a hired system gives the flexibility to adapt site capabilities rapidly and cost-effectively
  • Overcome budget challenges – dosing equipment hire is a relatively low monthly payment on the operating expenditure budget
  • Bring in external expertise – as specialists in their field, the chemical dosing equipment provider brings knowledge, skills, and capacity to install and maintain dosing equipment.

Although most water and wastewater businesses invest in their own chemical dosing equipment, as can be seen from the list above, there are times when hired systems become a welcome problem-solving option.

Bigger, in this case, is better

Due to the fact that WES Ltd has the biggest fleet of chemical dosing units for hire in the UK – with 350 individual assets – the company is well-used to meeting customer hire needs quickly and effectively. This response speed is especially important in the event of expected breakdowns or emergencies.

WES – a helping hand in an emergency

The team of experts at WES understands the potential damage a dosing system breakdown can have, particularly for wastewater treatment plants, where a failure can potentially lead to environmental damage and significant fines. WES has the ability to deliver a pre-configured system – often within the same day a hire-call is received – that can be installed and operating within hours, ensuring critical processes continue to function.

So, in these times where so many things are proving difficult to get hold of, WES is ready and able to meet any chemical dosing system need you have – be that planned or an emergency.

For further information on WES’ hiring service, click here

The importance of bunding for funding

Incidences of pollution will have a significant impact on funding throughout AMP7. It’s, therefore, vital that businesses involved in water and wastewater treatment focus on preventing chemical leakages. Hiring or purchasing bunds, structures that underly and wall-off areas containing hazardous chemicals or liquids, thereby providing containment in the event of leaks, represents a small investment. However, it drastically reduces the risks associated with storing chemicals.

Businesses have an array of choices to make when it comes to selecting a bund suitable for their needs. They can opt for a permanent bund, built directly on the treatment site or manufactured off-site, transported and then installed. Temporary or portable bunds, used for smaller volumes, meanwhile, are made from lighter materials. They include intermediate bulk containers (IBC) bunds, which when constructed for movement by forklift trucks are often referred to as pallet bunds.

The most suitable material for the bund must be considered and selected based on several factors, including the size of the storage containers, the nature of the chemical stored, and the bund’s position and environment. The decision is also strongly affected by whether it will be built on-site or manufactured off-site.

The most traditional permanent bunds are built with concrete, brick or block walls, standing on concrete floors. These materials, and any mortar used in the masonry walls, must be watertight and capable of resisting the chemicals.

In recent years, as off-site bund manufacture has grown in popularity, different materials and construction methods have become more common. One alternative for permanent bunds is prefabricated steel. However, this is susceptible to both atmospheric corrosion and attack by the stored chemical, so a special resistant coating must be applied to it.

Together with the growth in off-site and modular manufacture of chemical dosing systems, there has been a considerable evolution in bund construction methodology and design in recent years. For packaged systems up to around 30,000 litres, fabricated polyethylene (PE) or polypropylene (PP) bunds with a rectangular footprint are now commonplace. However, certain design issues must be addressed if they are to be considered viable alternatives to civil-engineered bunds constructed on-site.

When it comes to choosing the capacity of your bund, the UK WIMES: Water Industry Mechanical and Electrical Specifications stipulate that it should be 110% of the total storage capacity of the largest tank or 25% of the total capacity of all tanks, whichever is the greater. However, requirements for outdoor bunds may differ a little between individual water companies. Thames Water, for example, insists on sizing at 110%, while Yorkshire Water extends this to 130% in its own specifications.

Finally, bunds must be protected from the elements and rigorously maintained if they are to function correctly in the long term.

Taking all of this into account, the safest approach is often to buy or hire complete chemical storage and dosing equipment set-ups from WES. They come with the most appropriate bunds, as well as all necessary filling and safety systems, and all components are pre-assembled and pre-tested. For easy installation and integration with the plant’s existing operation, each delivery is also accompanied by the right pipework, connectors and control features.

Click here to download our full guide on bunding.

A large dose… an innovative approach to eutrophication

Phosphorus in wastewater is a key cause of eutrophication which is the over-enrichment of lakes and other surface waters from mineral and organic nutrients. It stimulates excessive growth of microscopic algae and plankton, creating a dense algal bloom, where the subsequent death and bacterial decomposition strips the water of its oxygen and creates an unhealthy environment. Eutrophication is a huge concern as many waterways and lakes in the UK are currently failing to meet the strict standards set for nutrient levels under the nation’s Water Framework Directive.

Agricultural fertiliser run-off from fields, detergents from household drains, and waste from various industries, are the main causes of phosphorus in the water. The levels in the discharges from municipal and industrial wastewater treatment plants must be controlled to minimise eutrophication issues. Such issues include increased purification costs to diminished recreational and wildlife conservation, loss of fish and other livestock, and potentially lethal effects from toxic algae in drinking water.

Drivers and challenges
Pressure from environmentalists and legislative demands in the UK to reduced phosphorus levels in discharged wastewater have been key drivers for one of WES’s key customers, Wessex Water. But how could the utility company find a new water treatment to tackle these issues, that was both cost-effective and practical, as well ensuring health and safety remained a focus?

One effective and commonly used step in the removal of phosphorus is to dose water with ferric chloride. And, so seeking increased or upgraded ferric dosing at multiple locations, Wessex Water issued a framework tender call, to which WES Ltd responded.

The first challenge for WES was to create a dosing system flexible enough to meet all control requirements and other product standards relating to Wessex Water, other water utilities and approved suppliers. An aspect essential to the system’s practicality was its size and weight. Every detail of the design also had to be weighed up in terms of its cost, to ensure the overall price was competitive. Ensuring they were resourceful and efficient with timings due to the potential risks poor weather might impact the project, were crucial considerations too.

WES established that it was able to answer these challenges and had the necessary equipment and capacity to manufacture, handle and transport units of each size. After presenting an outline plant design, its specialists worked closely with Wessex Water’s internal Engineering and Construction project team on developing it to meet their specific operational needs.

A package for all sites
Their innovative approach and thinking resulted in a cost-effective, compact and versatile package. Furthermore, its standardised approach, with broad applicability, enabled just two size variants, 5,000 and 10,000 litres, to address the different circumstances required at a large number of sites.

The use of a common rather than bespoke design contributed to the solution’s cost efficiency. Further time and expense were saved by fully constructing and testing each package in the controlled conditions at the WES factory in Basingstoke, before delivery, instead of assembling them on site.

Even the largest units could easily be handled in one lift and safely transported on a single, non-articulated, flatbed truck. Meanwhile, easy carriage and there relatively small dimensions gave them flexibility for installation on disparate sites, where space was often at a premium and the terrain could prove to be challenging.

The advantages of reducing time and labour costs meant that the number of personnel needed on site was also minimised. Moreover, the duration of their exposure to associated health and safety risks was especially welcomed, in view of the added hazards and complexities sometimes posed by adverse weather conditions.

Successful co-operation
Design, delivery and installation of the ferric chloride and ferric sulphate units initially ordered by Wessex Water took 9 months and the project was completed in summer 2018. Since then, WES Ltd has received dozens of orders for the supply of 5,000 and 10,000 litre systems by water utility companies and their contractors.

To WES, this project was particularly important as it established the company’s first formal framework co-operation with Wessex Water. For the water industry, that co-operation has produced a practical, affordable and adaptable answer to the challenge of complying with legislation aimed at reducing phosphorus levels. Its positive environmental impacts should be far-reaching.


For further information on how to remove phosphorus more cost-effectively, please see our white paper on the subject.