Pumps vs wet wipes

Across Australia and the world, water utilities are witnessing an increase in faults caused by non-
degradable materials entering sewer networks. Many of these issues can be largely attributed to wet wipes, which do not readily disintegrate when flushed down the toilet, despite many brands being advertised as ‘flushable’.

While the role of wet wipes in the creation of ‘fatbergs’ has received substantial media attention, wet wipes can also cause significant and costly damage to vital pumping infrastructure. We spoke to a number of water utilities across the country about some of the wet wipe-­related issues they’ve experienced in their networks and what they are doing to protect pumps, fight fatbergs and combat the wet wipe menace.

Sydney Water (NSW)

Wet wipes are a significant problem for Sydney Water. Keiran Smith, Manager Media and External Communications, and Charlie Kawtal, Systems Operations Officer, told Pump Industry that in the past two years alone, Sydney Water has removed over one million kilograms of wipes from its network at an annual cost of over $8 million.

Nationally, water utilities are spending over $15 million annually to remove wet wipes from their networks.

“If the wipes removed from the Sydney Water network each year were placed end to end they would stretch from Sydney to Los Angeles,” said Mr Smith.

“Wet wipes pose an environmental risk from overflows resulting from pumping station and overflow blockages, causing environmental and aesthetic issues in our creeks and waterways which are costly to clean up.

“As well, there is a safety risk to maintenance technicians and treatment plant operators who are required to clear wastewater blockages and filter screens.”

However, ‘flushable’ wipes can also create problems for customers before they even enter the larger wastewater network.

They can also block household plumbing, causing overflows inside the home and costly plumbing bills.

Sydney Water reports receiving an increasing number of notifications from customers and private plumbers about problems being caused by wet wipes in private sewer pipes.

One plumber claims that one in three of his call outs are the result of blockages caused by wipes, and one customer reported a plumbing bill of $16,000 to repair damage to her property’s plumbing caused by wipes.

“In many areas about 75 per cent of sewer blockages will have wet wipe materials either directly or indirectly responsible for the blockage.”

Sydney Water first identified its wet wipe problem due to an increased frequency of issues caused by non­biodegradable materials in its wastewater network.

“The problem with wet wipes was initially detected due to the increased dredging frequency of the wet wells in Sydney Water’s pumping stations, as the result of the build­-up of wipes,” said Mr Kawtal.

“There was also an increasing trend in faults at sewage pumping stations across the network. The cause of these faults was again largely attributable to the increasing disposal of non-­biodegradable wet wipes via the wastewater system. Further investigation revealed it was an escalating issue for water utilities around the world.”

According to Sydney Water, there are two main areas in its wastewater system where wet wipe blockages are likely to occur – small diameter reticulation pipes and pumping stations.

Small diameter reticulation pipes usually have low flow.

In addition to causing blockages directly, wipes can combine with tree roots or other minor obstructions within the pipes to cause blockages.

At pumping stations, wipes can get caught in the pumps, causing breakdowns.

Wastewater settles between pump operating cycles, leading to a build-­up of material that has not broken down, such as wipes.

These wipes can then get picked up by the pump during its next operating cycle.

To combat wet wipe related issues, Sydney Water is deploying a combination of operational innovations, public awareness campaigns and industry collaboration.

“Traditionally, wet wipe blockages were removed manually and as the problem has increased, Sydney Water has needed to put in place protocols to manage the process.

“At the Cronulla Wastewater Treatment Plant, as an example, step screens now dump the wipes into a water sluice which conveys them to a corkscrew press where liquid is removed and the dry wipes are deposited into a sealed tanker which takes the wet wipes away.

2.5 tonnes of these materials are removed from the Cronulla Plant every week.

“Sydney Water has 679 sewage pumping stations (SPS). Wet wipes accumulate over time in the well, causing many hazards and maintenance problems. Level sensors and instrumentation become blocked, pumps choked and odour builds up.

“Traditionally, maintenance crews have gone to SPS’s on a regular basis to manually clean the wet wells. Issues with this process include excessive water usage, high labour costs, confined space entry, pump chokes and ineffective cleaning.

“This time consuming and labour intensive process is very expensive with each SPS requiring on average five to six manual flushes per year.”

As a result, Sydney Water has introduced an automated process of self-­cleaning of wet wells on SPSs. This process also optimises performance of the SPS and has significantly reduced Sydney Water’s operating costs.

“The ‘auto­flushing’ was achieved by modifying the cut out levels of pumps during peak flows for each site via the use of the SCADA system.

“The concept is that if you started with a clean well you could keep it clean by running the pumps down to a low level near the top of the pump intake so that the pump would skim off the surface material.

“If done on a daily basis there would be no extra burden on the pumps and there would be no build­-up of material, leaving the well clean.

“This leads to no build­-up of material on the measuring instruments and large lumps no longer forming to choke pumps. Without build-­up of surface material odour is significantly reduced.

“The direct benefits of having an automated system was a significant reduction in cleaning costs, safety risks removed, corrections of other sewage pumping station faults during implementation, reduction in odour complaints and deferral of major capital outlay for equipment or construction.”

Knowing that an operational response was only part of optimising network performance, Sydney Water developed a multifaceted communications approach to better engage with the community to raise awareness and modify customer behaviour around flushing wipes.

Mr Smith said “Our customer research informed us that packaging claims have a direct influence on individual customer’s choice of wipes and leads to a higher prevalence of flushing these wipes down the toilet.”

Further our research found that:

• Approximately 1 in 3 wipes users flush, which equates to 1 in 4 of the total Sydney population over 15 years of age

• Intimate wipes are the key problem category and packaging claims are influential (more so for women)

• If customers perceive products as biodegradable, they twice as likely to flush them

• Males 15­44 years were the worst flushing offenders

“The survey also found 25 per cent of respondents indicated they would reduce wipes usage after knowing the cost and environmental impact, while 31 per cent would look to switch to another ‘biodegradable’ option.

“With this insight, the ‘Keep wipes out of the Pipes’ program was launched by Sydney Water in May 2015 across multiple communication platforms.

“The strategy was to engage and activate our customer base through creative social media posts that would raise awareness of the issue with a simple call to action,” said Mr Smith.

“The creative concepts, developed by HOST Sydney, aimed to bring a problem which mostly exists underground to the everyday consciousness of our customers. It was about converting an ‘out of sight, out of mind issue’ into one of everyday relevance.

“All materials produced featured a shocking statistic and the call to action to ‘Keep wipes out of the pipes’. These visuals were then able to be easily adapted for use across many channels, from social media, educational programs, right through to the Sydney Water bill.

“Building staff engagement through empowerment was an important element in the communications program. Sydney Water staff were brought along on the program through staff lunchtime sessions and given access to a ‘BBQ pack’ of key messages they are authorised to use with families and friends to build word­-of­-mouth networks to support the program.

“The media strategy has had a current cumulative reach of over 12 million people across print, online, radio and television. This includes Sydney Water and its spokespeople regularly being cited in the media.

“Our social media reach has exceeded one million people at an average engagement rate of 6 per cent, above the utility industry benchmark of 0.5­2 per cent.

Sydney Water’s education campaign on wipes has produced stunning results. Comparing the Sydney Water Consumer Sentiment Survey conducted for the March Quarter 2016 and those from the April/June Quarters in 2015 found that:

• There has been a 50 per cent reduction in the proportion of customers who think it’s OK to flush wet wipes

• There has been a 57 per cent reduction in acceptability of flushing baby wipes

• The number of 20­29 year olds (one of the target demographics) who think it’s OK to flush wipes has reduced by 54 per cent

• The number of people 50+ years old who think it’s OK to flush wipes has reduced by 61 per cent

• The number of males of all age groups who think it’s OK to flush wipes has reduced by 46 per cent.

This highly effective campaign also resulted in customer advocates questioning wet wipe packaging claims, including a CHOICE magazine investigation into the packaging claims made by wipes manufacturers, which culminated in a major brand being awarded a ‘Golden Shonky’ at the 2015 Shonky Awards in Sydney.

Over 5,000 people have joined CHOICE’s ‘Flushbusters’ campaign to have wipes products more appropriately labelled or removed from sale.

“Market­-leading wipes manufacturer Kimberly­-Clark has introduced ‘new and improved’ paper rather than plastic based Kleenex Flushable Wipes, along with a commitment to label their non­-flushable products with a distinctive ‘do not flush’ symbol.”

“Sydney Water has also closely supported WSAA’s successful approach to seek approval from Standards Australia to establish a mirror committee to the work of the international committee ISO/TC 224 WG 10 Flushable Products.

“Sydney Water is contributing technical expertise on behalf of the industry in the development of an international standard on ‘flush­ability’, which can be recognised by Australian water utilities as appropriate for local wastewater system characteristics,” said Mr Smith.

Yarra Valley Water (VIC)

Glenn Wilson, General Manager Infrastructure Services with Yarra Valley Water, said the introduction of ‘flushable’ wet wipes and other non-­degradable products into Yarra Valley Water’s sewerage network causes significant operational issues.

Materials that do not break down can cause issues in a number of places throughout the network of pipes and pumps:

• Smaller diameter pipes: small numbers of wipes or non-­degradable products can cause blockages at bends and fittings, or in the pipe itself (particularly when snagged by tree roots)

• Larger diameter pipes: large numbers of wipes or masses of non­degradable products can cause blockages as they can clump together, or combine with fats to cause bigger blockages

• Sewage Pumping Stations: material that flows through the network of upstream pipes will accumulate in the wells of pumping stations. These can block the pumps, preventing the station from being able to convey flows and in the worst case, overflowing

• Sewage Treatment Plants: non­-degradable products that pass through the inlet screens (these are designed to remove non-degradable materials from the flow stream) can cause damage to mechanical components and interrupt sewage treatment processes.

“Yarra Valley Water has not characterised the non­degradable material we have removed from the sewerage system, so it is not possible estimate what proportion of the material is made up of wet wipes,” said Mr Wilson.

“However, many of our Sewage Pumping Stations must be cleaned out frequently to remove the build­up of non- degradable materials that accumulate in the well.

“This material includes wet wipes, feminine hygiene products, and other items that have passed through the upstream network of pipes. Currently, Yarra Valley Water is forced to clean one of its larger facilities every three months.

“Every time, a mass of non­-degradable materials between 10 and 20 cubic metres in size is removed from the well.”

If sites are not cleaned out, the build­up of non­degradable material can cause significant operational issues, including:

• Pump blockages, and inability to re­seat pumps once they are put back into the well
• Damage to pumps, and excessive wear on pump impellers
• Fouling of instrumentation and interference with float level switches.

According to Mr Wilson, Yarra Valley Water’s operational teams have noticed an increase in issues caused by non- degradable products in recent years.

“Yarra Valley Water frequently experiences blockages in pumps at Sewage Pumping Stations and Sewage Flow Control Facilities.

“In these instances, wet wipes and non-­degradable materials pass into the well of the site from the upstream sewerage network. They tend to accumulate in the well, and clump together with other wipes and non­-degradable material.

The pumps at these sites are located at the bottom of the well, so when they start up, they draw the obstruction directly into the pump impeller. If a large enough obstruction remains lodged within the pump impeller preventing it from turning, the pump will stop and the level within the well will rise.

“Yarra Valley Water is alerted to the issue by a remote telemetry system and our maintenance contractor is sent out to correct the problem. We also have multiple pumps at all pumping stations to provide a level of redundancy.

“The blockages need to be removed manually, which requires the lid of the well to be opened, the pump to be lifted out by a crane, and the obstruction to be removed by hand.

“If the well is extremely dirty, and the pumps are blocking frequently as a result, the well must be cleaned out before the pumps are returned. This requires the maintenance contractor to use a vacuum truck to

remove the contents of the well. They will often need to isolate flows into the site and enter the well to ensure a thorough clean which is high-­risk work.”

Mr Wilson said that Yarra Valley Water had replaced some pumps in its network order to reduce blockages.

However, replacing pumps was not a suitable solution for every site.

“In recent years, pump manufacturers have been able to design pumps that are less susceptible to blockages.

“It is not possible for Yarra Valley Water to employ this technology at every site in its sewerage network due to the extreme cost in replacing all of the older pumps within the network, and also because pump selection must be primarily based around meeting the required duty point (being able to operate across the required flow range and lift the sewage to the discharge point).”

Yarra Valley Water has implemented a number of measures in response to the growing volume of non­degradable material in its sewerage network. These have included:

• Changing pumps at some sites to types better able to deal with non-­degradable material (e.g. chopper pumps, or pumps with impellers that are less susceptible to blockages)

• Installing macerators at inlets to sites

• Increasing the frequency of wet clean outs at sites which accumulate large quantities of non­-degradable material.

“The efficacy of these measures has varied, and they have not entirely prevented pump blockages from occurring,” said Mr Wilson.

“For example, while wet wipes and other non­-degradable materials may be macerated, the cut up material can reform together in pump wells over time and create an even larger blockage.

“Therefore, the fixes that involve the use of mechanical equipment have not removed the need for pump wells to be cleaned out.”

In addition, Yarra Valley Water is currently developing an education campaign in regards to the sanitation services it provides.

“It will cover what cannot be flushed down the toilet, as well as how to dispose of an array of items that are regularly flushed, and how the sewerage system works and is maintained,” said Mr Wilson.

The utility also employs targeted community engagement via newspaper and other media following any sewer spills determined to have been caused by large quantities of non-­degradable material.

“We are also participating in the development of an international standard for flushable products. Australia’s input to this committee is being coordinated by the Water Services Association of Australia,”said Mr Wilson.

Queensland Urban Utilities (QLD)

Queensland Urban Utilities has also experienced an increase in problems due to wet wipes in recent years.

Queensland Urban Utilities Manager of Trade Waste, Col Hester, said so­called ‘flushable’ wipes contribute to increased maintenance and disposal costs.

“Our treatment plant operators have noticed blockages caused by a build–up of ‘rag’ material on inlet screens have become significantly worse,” he said.

“Call outs to blockages at pump stations and fouled impellers are also on the rise. Not all of the foreign material is ‘flushable’ wipes, but a significant proportion usually is.

“It’s estimated we remove around 120 tonnes of wet wipes from our sewerage network every year, which if laid end-­to­-end, would stretch all the way from Brisbane to New Zealand.”

According to Mr Hester, wet wipes entering QUU’s sewer networks are a growing problem.

“Our operators are definitely reporting the problems associated with ‘flushable’ wipes are getting worse,” he said.

“We’re removing more ‘grit and screenings’ from inlet works at treatment plants and also spending more time maintaining pumps and other equipment.

“We spend about $2.5 million every year responding to more than 2,500 blockages in our network and wet wipes are largely to blame. They often combine with other nasties that people flush down the toilet or sink, such as cooking fats.

“Wet wipe accumulations have also necessitated increased pump station maintenance.

“So­-called ’flushable’ wipes are made from material that doesn’t break down like toilet paper. They also bind together with other wipes to form what we call ‘flushable ropes’.

“These ropes are damaging for pump stations as they wrap around the impellers, forcing the pumps to work at a harder duty cycle and become very inefficient.

“Responsive maintenance call outs to pump stations have increased considerably.

“Wipes also accumulate on protective screens at pump stations, requiring them to be manually removed and cleaned to allow the pump station to keep operating,” Mr Hester said.

“We’re attending an increased number of unplanned maintenance jobs at pump stations, so we’ve had to place some on higher maintenance frequencies.

“Screens at our sewage treatment plants are also now being cleared of wet wipes more frequently, and increased volumes are being removed for disposal to landfill. We’re currently spending around $600,000 a year removing this rubbish from our plants.

“In some cases the plant inlet screens simply aren’t able to deal with the amount of ‘rag’ coming in, forcing operators to manually remove it. This is very unpleasant and labour intensive work.”

QUU is undertaking a number of other initiatives in response to the wet wipe epidemic.

“We’ve launched a campaign to educate people about what should and shouldn’t be flushed. This includes billboards, website ads, social media and posters on the back of toilet doors at airports, shops, cinemas and pubs,” said Mr Hester.

“We’re also here to support the consumer watchdog, the Australian Competition and Consumer Commission (ACCC), in its investigation of whether manufacturers’ claims of flushability are deceptive and therefore a breach of consumer law.

“In addition, we’re working with other utilities through the Water Services Association of Australia (WSAA) to develop a standard method for assessing the flushability of products, as well as a way to determine ‘flushable’ wipe mass loads at points within our sewerage system.”

Mr Hester said that ongoing efforts will be required to combat the wet wipe problem.

“The campaign to educate people about the flushability of wipes is still new, so it’s too early to measure any behaviour changes.

“We undoubtedly need to continue with our communications effort to prevent ‘flushable’ wipes from entering the sewerage system.

“If the current trends continue, we may need to invest in redesigned pump impellers that can cope with the accumulation of wet wipes.”

South East Water (VIC)

South East Water is another Australian water utility that has had to make operational changes in response to problems caused by wet wipes.

“Last year South East Water took a look at blockages across 50 pump stations and found that 70 per cent were caused by ‘flushable’ wipes,” said Mark McCormack, General Manager for Network Services.

“Together with blockages caused by tree roots and fats and oils, ‘flushable’ wipes contribute towards South East Water’s more than $2.2million per year in sewer network maintenance costs.

“Our data indicates that the number of blockages at our pump stations has increased by around 20 per cent in recent years.

“Not only are we seeing an increase in pipe blockages caused by ‘flushable’ wipes, but our maintenance regimes are changing at our treatment plants, with more frequent clearing of inlet screens now necessary.

“If not screened out, these materials would cause problems for our treatment apparatus, and potentially impact on the quality of final effluent we could produce.”

Mr McCormack said that South East Water is undertaking media campaigns to raise public awareness of the issue, in addition to participating in industry collaborations aiming to bring about legislative change.

“South East Water regularly runs campaigns via our customer touch points, and also via the media.

“We are also focused on using the combined weight of our industry through the Water Services Association of Australia (WSAA) to drive legislative change, particularly on labelling and use of the term ‘flushable’.

“Progress is being made in this area although of course we would like things to move faster.”

“Once customers become aware that these products can cause blockages, not only in our networks but in households too, with messy toilet overflows and expensive repairs, it inevitably results in changed behaviour,” said Mr McCormack.

“We have also recently seen new products come onto the market that are paper­based and therefore break down more easily.”

“That said, we continue to see water companies across the country clearing tons of flushable wipe material from their networks. Only by changing the way these products are marketed and sold will we see significant change, and we’re hopeful that the work WSAA is leading will deliver a good outcome.”

SA Water (SA)

SA Water Senior Manager of Wastewater Operations, Lisa Hannant, said that while SA Water has so far avoided any particularly large fatbergs due to trade waste regulations limiting the greases and fats entering the sewers, wet wipes still pose a problem in the network.

“In the metropolitan area alone, SA Water spends around $400,000 a year combatting gross solids that collect at inlets to treatment plants, of which wet wipes form a large component,” said Ms Hannant.

SA Water field operators have reported increases in floating material in plants and blockages at pumps stations where fat, wet wipes and other material accumulate.

This has the potential to cause sewage overflows or backflows into customers’ properties.

“We do get pumps ragged up,” said Ms Hannant.

“But we can’t be sure it’s 100 per cent wet wipes.”

SA Water reviews its maintenance programs on an ongoing basis in response to performance data. Ms Hannant said that in one regional plant where rag balls were a recurring problem, SA Water changed the station’s operation to flush more regularly, delivering smaller rag balls more frequently.

The organisation is undertaking community engagement programs to raise customer awareness of the problems caused by flushing wet wipes, as well as working on a broader industry solution by participating in the international standard development with WSAA.

“We had an info brochure put in SA Water bills last year to raise awareness of the issues caused by wet wipes,” said Ms Hannant.

SA Water has also used Youtube, social media and an in­person education program involving SA Water staff speaking to community groups to engage the public.

“Community education is a key,” said Ms Hannant. “If people are aware of the problems wet wipes cause then that goes a long way to solving the problem.”

City West Water (VIC)

According to Theo Vlachos, Wastewater and Stormwater Manager at City West Water, wet wipes have caused an increasing number of blockages for some pumps within the City West Water wastewater network.

“The wet wipes clump together and cause pumps to block up, especially smaller sized pumps,” he said. “Wet wipes that do not get pumped out gather into large clumps and block pumps and other equipment.”

“Wet wipes are often the cause of blocked pumps, resulting in additional maintenance and repairs, which in turn drives operational costs upwards.”

In some cases, pumps particularly prone to faults have been replaced with pump designs more resistant to clogging.

“We have changed pumps that are better designed to tolerate wet wipes and rags—they don’t get caught as often,” said Mr Vlachos.

“We may need to monitor pumps that are blocking up more often to discover what is the main cause – is it a build­-up of wet wipes or other material?”

City West Water has also participated in public awareness campaigns about the blight of wet wipes.

“We joined with the other two metro water companies to provided statements on our website and regular messages on our social media channels. We highlighted CHOICE Magazine giving flushable wipes a ‘Shonky Award’, for example, to show that no wipes should be flushed down the toilet.”

However, Mr Vlachos says there is still work to be done and changing public attitudes towards what can be flushed down the toilet is vital.

“We’ve seen a decrease in the problem, but that could be more to do with changing to better designed pumps rather than changes to customer behaviour. We always repeat the message that no wet wipe is flushable – if consumers take this on board we’d have no problems with wet wipes in the sewer system.”

These are just some examples of the ways Australian water utilities are working to defeat the wet wipe scourge and prevent damage to pumps and other infrastructure.

Wet wipes entering wastewater networks is an ongoing problem worldwide, and one that will likely require a combination of measures to solve.

Such measures may include pump design improvements and other operational solutions, effective industry collaboration, the development of the international standard for flushable products and continued public engagement.

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