14. Sewage treatment plant

A sewage treatment plant, often referred to as a wastewater treatment plant, is a facility designed to receive, treat, and process domestic, industrial, and commercial sewage to remove contaminants and pollutants from the wastewater before it is released back into the environment or returned for reuse. These treatment plants are typically used in areas where a centralised sewer system is not available or practical.

Here is how a sewage treatment plant typically works:

Collection	Wastewater from various sources, including toilets, sinks, showers, and industrial processes, is collected and conveyed to the sewage treatment plant through a network of underground pipes or septic systems.
Preliminary treatment	In the first stage, large solid objects, such as sticks, rags, and debris, are removed from the incoming wastewater to prevent damage to pumps and equipment. This is often done through the use of screens or grates.
Primary treatment	In this stage, the sewage is settled in large tanks, allowing solid particles to settle to the bottom. This process forms a sludge layer, while relatively cleaner water rises to the top. The sludge is removed and further processed or treated separately.
Secondary treatment	After primary treatment, the remaining liquid undergoes secondary treatment, which is a biological process. Microorganisms are introduced into the wastewater to consume organic matter and pollutants, breaking them down into simpler, less harmful substances. Common secondary treatment methods include activated sludge processes, trickling filters, or biological contactors.
Tertiary treatment (optional)	Depending on the treatment plant's requirements and environmental regulations, additional treatment steps may be employed to further purify the wastewater. This can involve advanced filtration, chemical treatment, or UV disinfection to remove any remaining contaminants.
Discharge or reuse	The treated wastewater, now significantly cleaner and safer, is either discharged into a receiving water body (e.g., river or ocean) or used for non-potable purposes like irrigation, industrial processes, or cooling water. In some cases, the treated water can be further disinfected to meet specific reuse standards.
Sludge management	The sludge generated during primary and secondary treatment is subjected to further processing, which may include thickening, dewatering, and, in some cases, anaerobic digestion to reduce its volume and convert it into biogas or biosolids for safe disposal or beneficial use as fertiliser.

Sewage treatment plants play a crucial role in safeguarding public health and protecting the environment by ensuring that sewage and wastewater are effectively treated before being released or reused. Proper maintenance and adherence to regulatory guidelines are essential to ensure the reliable and efficient operation of sewage treatment plants.

Regulations

Compliance with British Standards	When considering the compliance of your sewage treatment plant with British Standards, it is important to be aware that these standards may have evolved over time. Older sewage treatment plants might not meet the latest standards, but they could still conform to the regulations that were in place at the time of installation. To assess compliance, it is advisable to have a professional inspection conducted, especially if your system has been in operation for many years.
Satisfaction of Environment Agency’s General Binding Rules (GBR)	The Environment Agency’s General Binding Rules (GBR) in England set out specific requirements for sewage treatment systems, with a focus on protecting the environment, particularly watercourses and groundwater. Compliance with GBR involves adhering to discharge limits, ensuring proper wastewater treatment, and, in some cases, using low-impact systems. To confirm compliance, review your system's specifications and ensure they align with these regulations.
Water flow destination (watercourse or land)	Understanding where the treated wastewater from your sewage treatment plant flows is crucial for environmental conservation. If your system discharges into a watercourse, it is imperative that the discharged water meets quality standards to prevent contamination. If the discharge is onto land, the soil must have suitable drainage capacity to prevent waterlogging. Soil testing can determine its suitability for this purpose.
Overflow or soakaway system presence	An overflow or soakaway system serves as a safety measure for your sewage treatment plant. It is designed to handle excess wastewater during emergencies, preventing flooding of the drain field or soakaway area. Ensuring this system functions correctly is vital, especially during periods of heavy usage or rainfall, to avoid overflows and system damage.
Location within property boundaries	The positioning of sewage treatment plant components within your property's boundaries can influence property ownership, maintenance responsibilities, and potential disputes with neighbours. If any part of the system extends beyond your property boundaries, legal agreements or easements may be necessary to secure access and maintenance rights.
Consents from regulatory bodies	Regulatory consents are essential for the legal operation of sewage treatment plants. In the UK, these consents are typically issued by the Environment Agency (EA) or local environmental authorities. To obtain these consents, you must demonstrate that your sewage treatment system complies with environmental and safety standards, which may involve submitting detailed plans and conducting soil tests.
Enforcement actions and pending actions	Enforcement actions may be taken if your sewage treatment plant is found to be non-compliant with regulations. Past enforcement actions should be disclosed, as they indicate a history of non-compliance. Pending actions can impact property transactions and system usage. It is crucial to address these actions promptly to resolve compliance issues.
Emptying frequency and cost	The frequency of emptying your sewage treatment plant depends on various factors, including its size, household size, and usage. Smaller systems typically require more frequent emptying. Costs can vary widely based on your location and service provider. Regular maintenance and scheduled emptying are essential to prevent system failure and ensure efficient operation.

Other considerations

System condition and blockages	Monitoring the condition of your sewage treatment plant is critical for its longevity and effectiveness. Regular professional inspections can help identify issues early. Blockages may occur due to improper use or system problems. Timely resolution of blockages is vital to prevent damage and maintain proper system operation.
Neighbour complaints and disputes	Neighbor complaints often revolve around issues such as odours, overflows, or perceived environmental impacts. Addressing these concerns proactively can help prevent disputes. Maintaining open communication with neighbours and considering the installation of odour control measures can mitigate potential issues.
Maintenance and repair agreements	When multiple properties share a sewage treatment system, agreements covering maintenance and repair responsibilities are essential. These agreements define who is responsible for costs and upkeep. It is crucial to have these agreements in writing and legally binding to avoid disputes and ensure the system's proper maintenance.
Sharing costs and disputes	The allocation of costs for sewage system repairs or maintenance should be clear and agreed upon by all parties involved. Disputes can arise when one party feels unfairly burdened. Legal agreements can help resolve these disputes, and in some cases, mediation may be necessary to find a satisfactory resolution.