Hidden in the recesses of our buildings, behind walls and ceilings, lie cold water storage tanks—unseen yet indispensable. These tanks silently hold the lifeblood of our daily routines, ensuring that clean, potable water flows through our taps and showers. But what happens when these reservoirs become breeding grounds for contaminants?
How do we maintain their purity and safeguard our health? In this comprehensive guide, we’ll dive into the depths of cold water tank cleaning and maintenance.
The Hidden Dangers of Neglect
When left unmaintained, these tanks can become breeding grounds for contaminants. Sediments, algae, and bacteria like legionella can accumulate, posing significant health risks. That’s why it’s really important to keep a close eye on these tanks and clean them regularly.
Why is Cold Water Tank Cleaning Necessary?
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Contaminants Lurking in the Shadows:
- Over time, dirt, dust, debris, and even harmful bacteria like legionella can accumulate in cold water tanks.
- Neglecting regular cleaning allows these contaminants to thrive, compromising water quality and safety.Because of the health risks, there’s a legal responsibility for those managing these water systems. This includes getting a Legionella Risk Assessment to identify potential hazards, setting up a Legionella Risk Management Programme to control and reduce risks, implementing and managing precautions to prevent the growth of Legionella, and keeping records of all these activities. These steps are crucial to ensure safety and compliance with health regulations. Learn more on legionella here.
- The Risks We Face:
- Bacteria and Pathogens: Stagnant water provides a fertile breeding ground for bacteria and viruses. Legionella, notorious for causing legionnaires’ Disease, finds solace in rust, algae, and sludge within these tanks.
- Biofilms: These slimy layers form due to UV radiation, limited nutrients, and other factors. Biofilms harbor pathogens and contaminate the water.
- Sediment: Metals dissolve over time, settling as sediment at the tank’s bottom. While not directly harmful, sediment can affect taste and odor.
- Legal Compliance and Health Assurance:
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- Regular cleaning aligns with guidelines such as HSG274 and ACoP L8.
- It ensures that your water remains clean, safe, and compliant.
ACoP L8: The “Approved Code of Practice and Guidance on Regulations L8” (ACoP L8) is a document published by the Health and Safety Executive (HSE) in the UK. It provides practical advice on how to comply with the law in terms of controlling Legionella in water systems. ACoP L8 is designed to help duty holders, including employers, those in control of premises, and those with health and safety responsibilities for others, to comply with their legal duties in this area.
HSG274: This is a series of technical guidance documents that are part of the HSE’s Legionnaires’ disease series. HSG274 provides specific guidance on the control of Legionella in different types of water systems. It’s divided into three parts: Part 1 deals with evaporative cooling systems, Part 2 covers hot and cold water systems, and Part 3 addresses other risk systems.
Together, ACoP L8 and HSG274 offer comprehensive guidance on assessing the risk of Legionella, implementing control measures, and maintaining water systems to prevent the proliferation of the bacteria. They emphasise the importance of regular monitoring, cleaning, and maintenance of water systems, as well as keeping records of all safety-related activities. Following these guidelines is crucial for ensuring the health and safety of individuals who might be exposed to water systems in various settings, such as workplaces, public buildings, and residential properties.
The Art and Science of Tank Cleaning
Cleaning these cold water storage tanks is a critical and detailed process. It’s not just about removing visible dirt; it involves draining the tank, meticulously removing sediments, disinfecting the interior, and ensuring no harmful residue is left behind. This process safeguards the water quality and, by extension, our health.
More Details on Tank Cleaning:
- Initial Inspection and Preparation: The first step is a thorough inspection of the tank. This helps identify any existing issues like cracks, leaks, or signs of corrosion. Before starting the cleaning process, it’s important to ensure that the tank is isolated from the water system to prevent contamination during cleaning.
- Draining the Tank: The next step is to completely drain the tank. This allows for a thorough examination of the interior surfaces and helps in identifying any sediment buildup, biofilm, or signs of corrosion that might not be visible when the tank is full.
- Sediment Removal: Over time, sediments can accumulate at the bottom of the tank. This sediment can include minerals, dirt, and other particulates that have settled over time. Removing these sediments is crucial as they can harbor bacteria and other microorganisms. This is usually done by manually scooping out the sediment or using specialised vacuums.
- Disinfecting the Interior: After sediment removal, the next critical step is disinfection. This involves using specific chemical agents or treatments designed to kill bacteria and other harmful microorganisms. The choice of disinfectant depends on several factors, including the tank material and the type of contamination. Care must be taken to ensure that the disinfectant is applied to all interior surfaces.
- Rinsing and Flushing: Post-disinfection, it’s essential to thoroughly rinse and flush the tank to remove any residues of the cleaning and disinfecting agents. This is important to ensure that the water stored in the tank post-cleaning is safe for use.
- Final Inspection and Testing: After the cleaning and disinfecting process, a final inspection is conducted. This might include testing the water for microbiological contaminants to ensure that the cleaning process has been effective.
- Documentation and Record Keeping: Keeping detailed records of the cleaning process, including the methods used, chemicals applied, and results of any post-cleaning testing, is essential. This documentation is important for regulatory compliance and future maintenance planning.
This comprehensive cleaning process ensures that the cold water storage tanks remain a reliable source of clean water. It’s a critical component of maintaining water quality and, consequently, protecting public health. Regularly undertaking this process is key to preventing the growth and spread of harmful bacteria like Legionella and ensuring the longevity of the water storage infrastructure.
Consistent Maintenance for Long-term Purity
Regular inspections and cleaning are key to maintaining tank purity. These preventive measures help identify potential issues like leaks or early signs of contamination. Additionally, routine cleaning, whether annual or biannual, is essential in preventing the buildup of harmful substances.
More Details on Long-Term Purity
Consistent maintenance is vital for ensuring the long-term purity of water in cold storage tanks. Let’s dive into why regular inspections and cleaning are crucial:
- Regular Inspections: These are essential to detect any potential problems before they escalate. During an inspection, professionals look for signs of wear and tear, corrosion, leaks, or any damage that could compromise the tank’s integrity. Inspections also involve checking for any early indicators of biological contamination, such as algae growth or biofilm development, which can lead to more serious issues if left unchecked.
- Preventing Contamination: Regular maintenance helps in preventing the buildup of harmful substances like sediments, bacteria (including Legionella), and algae. If these contaminants accumulate, they can not only affect the taste and smell of the water but also pose significant health risks.
- Cleaning Frequency: The frequency of cleaning depends on various factors, including the size of the tank, its usage, the water quality in the area, and environmental conditions. In general, it’s recommended to clean water tanks at least once a year, but in some cases, more frequent cleaning, like biannually, might be necessary.
- Routine Cleaning Process: This involves emptying the tank, thoroughly scrubbing and removing any sediment or deposits, and then disinfecting it. After cleaning, the tank should be rinsed and flushed properly to ensure no cleaning agents are left behind.
- Leak Prevention: Regular maintenance also includes checking and repairing any leaks. Leaks not only waste water but can also introduce contaminants into the tank, compromising the water quality.
- Record Keeping: Maintaining a log of all inspections, cleanings, and repairs is essential for tracking the tank’s condition over time. This record helps in planning future maintenance and can be crucial for regulatory compliance.
- Professional Expertise: While some aspects of maintenance can be handled in-house, it’s often beneficial to engage professionals, especially for more comprehensive inspections and cleaning. Professionals have the necessary equipment and expertise to carry out the task effectively and safely.
In summary, consistent maintenance of cold water storage tanks is key to ensuring water quality and safety. Regular inspections and cleaning not only help in maintaining the purity of the water but also extend the lifespan of the tank, ensuring a reliable supply of clean water for the long term.
Seeking Professional Expertise
There are instances where the complexity of tank maintenance necessitates professional expertise. Water quality specialists have the tools and knowledge to ensure tanks not only remain clean but also adhere to health and safety standards.
More reason to seek professional expertise:
- Complex Maintenance Needs: While some basic maintenance tasks can be managed in-house, many aspects of water tank maintenance can be complex and require specialised knowledge. This is particularly true for larger tanks, tanks in critical facilities, or tanks that have shown signs of significant contamination or damage.
- Expert Assessment: Water quality specialists are trained to assess and address a variety of issues that might not be immediately apparent to the untrained eye. They can conduct thorough inspections, identify potential risks, and provide recommendations for corrective actions.
- Advanced Tools and Equipment: Professionals have access to advanced tools and equipment that are essential for effective cleaning, inspection, and repair of water storage tanks. This includes high-pressure cleaners, underwater cameras for internal inspections, and specific tools for repairing or replacing tank components.
- Compliance with Regulations: Water quality and safety are subject to various health and safety regulations. Professionals are up-to-date with these regulations and can ensure that your tank maintenance complies with the latest standards. This is crucial to avoid legal issues and to ensure the safety of those using the water.
- Effective Disinfection Techniques: Properly disinfecting a water tank is a critical part of maintenance, and it requires specific knowledge about the types of disinfectants to use and their proper application. Professionals can ensure that the disinfection process is thorough and effective, without leaving harmful residues.
- Handling Complex Contaminations: In cases of severe contamination, such as a Legionella outbreak, professional expertise is essential. These situations require a targeted and strategic approach to eradicate the bacteria and prevent its recurrence.
- Long-Term Maintenance Planning: Beyond immediate repairs and cleaning, water quality specialists can provide valuable insights for long-term maintenance planning. They can suggest improvements, upgrades, and a maintenance schedule tailored to the specific needs of your water storage system.
- Training and Education: Professional services often include educating the client about basic maintenance and monitoring practices. This knowledge transfer can be valuable in maintaining water quality between professional cleanings.
In summary, seeking professional expertise for water tank maintenance is crucial for ensuring the safety, efficiency, and longevity of your water storage system. The specialised skills and tools that professionals bring to the table are invaluable in maintaining the highest standards of water quality and compliance with health and safety regulations.
Technical Standards and Chlorination Procedures
Professional water tank cleaning extends beyond simple debris removal, requiring systematic procedures that ensure microbiological safety and regulatory compliance. Understanding these technical requirements helps facilities managers appreciate the complexity and importance of professional tank maintenance.
Chlorination Protocols and Disinfection Standards The chlorination process follows strict protocols outlined in BS 8558:2015 and HSG274 Part 2. Initial shock chlorination requires 50mg/l free chlorine concentration, maintained for minimum one hour contact time. This concentration effectively destroys biofilm and kills resistant organisms including Legionella pneumophila. Temperature monitoring ensures chlorine effectiveness – higher temperatures require increased concentrations due to accelerated chlorine degradation.
Post-chlorination flushing removes residual chlorine to acceptable levels below 0.5mg/l for domestic systems. Multiple sampling points verify complete system disinfection. Water sampling at 48 hours post-chlorination confirms microbiological safety before returning systems to service. Documentation includes chlorine concentrations, contact times, and neutralisation procedures, providing audit trails for compliance verification.
Tank Inspection Technologies and Assessment Methods Modern inspection techniques utilise underwater cameras and remote operated vehicles (ROVs) for large tanks, eliminating confined space entry risks. Ultrasonic thickness testing identifies corrosion without tank drainage. Thermal imaging detects insulation failures and temperature stratification. These technologies enable comprehensive assessment while minimising system disruption.
Professional inspections evaluate structural integrity including weld conditions and support structures, internal coatings for degradation or failure, inlet/outlet configurations affecting water turnover, overflow and warning pipe functionality, and insect screen integrity preventing contamination. Detailed photographic records document conditions, supporting maintenance planning and insurance claims.
Integration with Comprehensive Water Hygiene Management
Cold water tank maintenance forms one element of holistic water safety programmes. Understanding these interconnections ensures comprehensive protection against waterborne pathogens.
Legionella Risk Management Integration Legionella risk assessments identify tanks as critical control points requiring specific management. Temperature monitoring ensures cold water remains below 20°C, preventing Legionella growth. Turnover calculations verify water doesn’t stagnate, creating growth opportunities. Tank design modifications eliminate dead legs where bacteria proliferate.
When assessments identify risks, legionella remedial works address root causes. Installing recirculation pumps improves turnover. Adding insulation prevents solar gain raising temperatures. Modifying pipework eliminates stagnation points. These engineering controls provide permanent risk reduction superior to repeated chemical treatments.
Temperature Stratification and Control Temperature stratification in tanks creates zones supporting bacterial growth. Solar gain on roof-mounted tanks raises upper layer temperatures into Legionella growth range (20-45°C). Poor mixing allows these warm zones to persist despite adequate inlet temperatures. Strategic inlet positioning and mixing systems prevent stratification.
Integration with air conditioning systems helps control plant room temperatures, preventing tank warming. Ventilation installation provides airflow reducing ambient temperatures. Reflective coatings and shading reduce solar gain. These passive measures maintain temperatures without energy consumption.
Water Quality Parameters Beyond Microbiology Comprehensive tank maintenance addresses multiple water quality parameters. pH affects chlorine effectiveness and corrosion rates. Turbidity indicates particulate contamination requiring investigation. Dissolved oxygen levels influence bacterial growth and corrosion. Conductivity changes suggest contamination ingress.
Chemical parameters require careful management. Iron and manganese from corrosion affect taste and stain fixtures. Copper from pipework poses health risks at elevated levels. Lead from older systems requires immediate attention. Regular monitoring identifies deterioration before affecting occupant health.
Sector-Specific Tank Cleaning Requirements
Different sectors face unique challenges requiring tailored tank maintenance approaches. Understanding sector requirements ensures appropriate service delivery.
Healthcare Facility Requirements Hospitals and care homes operate under enhanced water safety requirements protecting vulnerable patients. Augmented care units require monthly temperature monitoring and quarterly tank inspections. Chlorination procedures must consider patient sensitivities and medical equipment compatibility. Documentation supports Care Quality Commission inspections.
Multiple tank systems serving different departments require coordinated maintenance minimising disruption. Theatre sterile services cannot tolerate supply interruptions. Dialysis units require consistent water quality. Emergency tanks must remain operational during primary tank maintenance. Our planned maintenance programmes coordinate complex healthcare requirements.
Food Processing and Manufacturing Food production facilities require water meeting specific quality standards. Product water requires enhanced monitoring beyond potable standards. Process water contamination causes product recalls and reputation damage. Cleaning chemicals must be food-safe preventing product contamination. Validation procedures verify cleaning effectiveness.
Integration with commercial refrigeration cooling towers prevents cross-contamination. Kitchen extraction cleaning coordinates with tank maintenance minimising production disruption. HACCP protocols incorporate tank cleaning as critical control points. These integrated approaches ensure food safety throughout facilities.
Educational Institutions Schools face unique challenges with extended closure periods creating stagnation risks. Summer holidays allow comprehensive tank cleaning without disruption. Pre-term chlorination ensures safe water for returning students. Multiple buildings with interconnected systems require systematic approaches.
Budget constraints demand cost-effective solutions without compromising safety. Combining tank cleaning with other maintenance maximises efficiency. PAT testing and fixed wire testing during holidays streamlines compliance. Student education programmes promote water conservation and hygiene awareness.
Residential and Commercial Properties Apartment buildings and office complexes serve diverse populations with varying vulnerabilities. Elderly residents and those with compromised immunity require enhanced protection. 24/7 occupancy prevents extended shutdown for maintenance. Tenant communication ensures cooperation during cleaning procedures.
Fire safety systems rely on adequate water supplies from tanks. Sprinkler system tanks require special consideration maintaining operational readiness. Fire damper testing coordinates with tank maintenance ensuring comprehensive safety compliance. Insurance requirements often exceed regulatory minimums.
Advanced Tank Design and Modification Solutions
Modern tank designs incorporate features facilitating maintenance and preventing contamination. Retrofitting existing tanks with these features improves water quality and reduces maintenance requirements.
Contamination Prevention Measures Properly designed tanks prevent contamination through multiple barriers. Sealed covers prevent debris and pest ingress. Double-skinned lids with insulation prevent condensation dripping into water. Insect screens on overflows and vents block entry while maintaining ventilation. Access hatches positioned above water level prevent contamination during inspections.
Retrofitting improvements address common problems. Installing proper covers on open tanks eliminates major contamination source. Adding screened vents prevents insect entry. Raising access points above water level improves safety. Sealing penetrations prevents ingress around pipework. These modifications provide permanent improvements reducing cleaning frequency.
Circulation and Turnover Optimisation Effective water circulation prevents stagnation supporting bacterial growth. Inlet and outlet positioning creates flow patterns ensuring complete turnover. Multiple tanks should operate in parallel rather than series, preventing extended residence times. Recirculation systems maintain movement during low-demand periods.
Computational Fluid Dynamics (CFD) modelling optimises modifications before implementation. Baffle plates direct flow preventing short-circuiting. Inlet diffusers prevent sediment disturbance. Outlet configurations ensure oldest water leaves first. These design improvements dramatically reduce contamination risks.
Material Selection and Coating Systems Tank materials significantly impact maintenance requirements and water quality. Glass-reinforced plastic (GRP) resists corrosion but requires UV protection. Stainless steel provides excellent durability but costs more initially. Galvanised steel requires protective coatings preventing zinc leaching.
Internal coatings must meet water contact approval standards. Epoxy coatings provide excellent protection but require proper application. Polyurethane systems offer flexibility accommodating movement. Cement-based coatings suit concrete tanks. Regular coating inspections identify degradation before affecting water quality.
Emergency Response and Contamination Management
Despite preventive measures, contamination incidents require rapid, effective response. Understanding emergency procedures minimises health impacts and business disruption.
Contamination Detection and Initial Response Early detection enables prompt intervention before widespread exposure. Unusual taste, odour, or appearance triggers immediate investigation. Illness clusters suggest waterborne transmission requiring urgent action. Routine sampling detecting contamination initiates response protocols.
Immediate actions include isolating affected tanks preventing further exposure, notifying authorities and affected occupants, implementing alternative water supplies, and initiating investigation identifying contamination sources. Speed proves crucial – delays increase exposure and liability.
Remediation Procedures and Verification Contamination remediation requires systematic approaches addressing root causes. Physical cleaning removes visible contamination and biofilm. Hyperchlorination destroys microorganisms throughout systems. Multiple flushes remove contamination and treatment chemicals. System modifications prevent recurrence.
Verification confirms successful remediation before returning to service. Water sampling at multiple points ensures complete decontamination. Sequential negative samples provide confidence in safety. Enhanced monitoring continues post-incident detecting any recurrence. Documentation demonstrates appropriate response for regulatory and insurance purposes.
Business Continuity During Tank Issues Tank problems shouldn’t halt operations with proper contingency planning. Temporary water supplies maintain essential services. Bottled water provides drinking supplies. Tanker deliveries supply bulk water. Portable tanks offer temporary storage. These measures maintain operations during repairs.
Coordination with other building services ensures comprehensive response. Air conditioning servicing may require adjustment without cooling tower makeup water. Kitchen operations need alternative supplies. Emergency procedures require regular testing ensuring effectiveness when needed.
Regulatory Compliance and Documentation Requirements
Comprehensive documentation demonstrates compliance protecting against prosecution and supporting insurance claims. Understanding requirements ensures adequate record keeping.
Legal Framework and Enforcement The Health and Safety at Work Act 1974 provides overarching duties ensuring safe water supplies. The Control of Substances Hazardous to Health Regulations 2002 specifically addresses Legionella risks. Water Supply (Water Quality) Regulations cover potable water standards. Building Regulations Part G addresses water storage requirements.
Enforcement authorities including HSE, Environmental Health, and water undertakers have powers to inspect, sample, and prosecute non-compliance. Improvement notices require specific actions within timeframes. Prohibition notices halt operations until compliance achieved. Prosecutions result in unlimited fines and potential imprisonment for serious breaches.
Documentation Standards and Requirements Comprehensive records demonstrate compliance and due diligence. Risk assessments identify hazards and control measures. Written schemes detail maintenance requirements and responsibilities. Logbooks record temperatures, cleaning, and inspection results. Certificates verify professional cleaning and chlorination.
Digital management systems increasingly replace paper records. Cloud storage ensures records remain accessible and backed up. Automated reminders prevent missed maintenance. Photo documentation provides visual evidence of conditions. Electronic signatures verify task completion. These systems streamline compliance while reducing administrative burden.
Insurance and Liability Considerations Insurance policies typically require evidence of proper tank maintenance. Non-compliance may void coverage leaving businesses exposed to claims. Public liability insurance covers third-party injury from contaminated water. Business interruption insurance covers losses during tank-related closures.
Professional indemnity insurance covers contractors’ liability for inadequate service. Method statements and risk assessments demonstrate professional competence. Training certificates verify engineer qualifications. Quality assurance systems ensure consistent service delivery. These measures protect both contractors and clients.
Cost-Benefit Analysis of Professional Tank Maintenance
Investment in professional tank maintenance delivers returns through multiple channels. Understanding complete benefits justifies maintenance expenditure.
Direct Cost Savings Preventive maintenance costs fraction of emergency remediation. Regular cleaning extends tank lifespan deferring replacement costs. Early problem detection prevents expensive system damage. Maintained water quality reduces treatment chemical consumption. Energy savings from efficient systems offset maintenance costs.
Professional cleaning typically costs hundreds while contamination remediation costs thousands. Tank replacement costs tens of thousands including installation and disruption. Business interruption during emergencies devastates revenue. Legal costs from prosecution or claims dwarf maintenance investments. These comparisons demonstrate maintenance value.
Health and Productivity Benefits Clean water supplies support occupant health reducing sick days. Improved water quality enhances satisfaction and morale. Reliable supplies prevent operational disruptions. Compliance confidence reduces management stress. Professional maintenance protects organisational reputation.
Studies show waterborne illness outbreaks cost businesses significantly through direct medical costs, lost productivity, legal liability, reputation damage, and regulatory penalties. Single Legionnaires’ disease cases cost hundreds of thousands in total impact. Prevention through maintenance proves highly cost-effective.
Strategic Business Advantages Demonstrated water safety compliance provides competitive advantages. Tender requirements increasingly demand evidence of water hygiene management. Insurance premiums reflect risk management quality. Property values benefit from documented maintenance. Sustainability credentials include water stewardship.
Forward-thinking organisations recognise water safety as business imperative rather than compliance burden. Integrated management with other services like solar PV and air source heat pumps demonstrates comprehensive sustainability commitment. Electric vehicle charging infrastructure shares water supply considerations. These synergies maximise investment value.
Future Developments in Tank Technology and Maintenance
Emerging technologies transform tank maintenance from reactive to predictive. Understanding developments helps plan future investments.
Smart Monitoring and IoT Integration Internet of Things sensors continuously monitor tank conditions. Temperature sensors detect stratification and solar gain. Level sensors identify leaks and overflow risks. Turbidity monitors detect contamination ingress. Water quality probes track multiple parameters simultaneously.
Real-time data enables predictive maintenance. Trend analysis identifies developing issues before becoming critical. Automated alerts notify of parameter deviations. Remote monitoring reduces site visits while improving oversight. Machine learning algorithms optimise maintenance schedules based on actual conditions rather than fixed intervals.
Advanced Materials and Coatings Antimicrobial materials actively prevent bacterial growth. Silver ion technology provides continuous protection. Photocatalytic coatings break down organic contaminants. Self-cleaning surfaces reduce maintenance requirements. Nano-coatings prevent biofilm formation.
Smart materials respond to conditions. Temperature-responsive polymers regulate heat transfer. pH-sensitive coatings indicate water quality changes. Self-healing materials repair minor damage automatically. These advances promise reduced maintenance with improved performance.
Sustainable Water Management Integration Rainwater harvesting increasingly supplements mains supplies requiring careful management. Grey water recycling demands enhanced treatment and monitoring. Ozone treatment provides chemical-free disinfection. UV systems offer point-of-use protection. These technologies support water conservation while maintaining safety.
Circular economy principles drive water reuse strategies. Heat recovery from tank overflows preheats incoming water. Overflow harvesting irrigates landscapes. Drain water supplies air source heat pumps. These integrations maximise resource efficiency while maintaining water quality.
Partnering with Enviro FWA for Water Tank Excellence
Cold water storage tanks require professional attention to ensure water safety and regulatory compliance. From routine cleaning to emergency remediation, proper tank management protects your organisation, employees, and reputation.
Enviro FWA provides comprehensive water tank cleaning and chlorination services across Northern Ireland. Our experienced engineers combine water hygiene expertise with broader facilities management capabilities, delivering integrated solutions that ensure your water systems remain safe and compliant.
Our holistic approach addresses all aspects of water safety. From legionella risk assessments to remedial works, water sampling to tank modifications, we provide complete support ensuring your water systems protect rather than threaten health.
Contact Enviro FWA today to discuss your water tank maintenance requirements. Whether scheduling routine cleaning, addressing contamination incidents, or upgrading ageing infrastructure, our expert team delivers solutions that safeguard your water quality while optimising operational costs.
