A growing number of people with interests in recycling biosolids, particularly on agricultural land, need to be satisfied the practice is safe. This has resulted in increasing regulation and a promised revision of the 1986 EC directive. Codes of practice and quality assurance protocols need to be complied with, if the practice is to be sustained.

The agreement between the water industry and the British Retail Consortium has been the most significant development in biosolids recycling since the 1986 EC directive. The former gave rise to the Safe Sludge Matrix, the details of which will be incorporated in new UK regulations and code of practice early this year. The code will require monitoring and auditing of sludge treatment processes and increased sampling and analysis frequency. The anticipated review of the EC directive is expected to include a requirement for better monitoring of treatment conditions as well as a phased approach to tightening metal levels.

The requirements of the regulations and codes of practice are many and varied, with compliance dependent on a number of interrelated criteria. It is incumbent on the water company as the sludge producer, to carry out the specified sampling and analysis, record details of applications to land – including the land’s ownership and location – and provide detailed information to the landowner once the applications have been made. Failure in any aspect of the process means the biosolids producer cannot honestly claim to be fully compliant.

While this may not lead to prosecution, missing data may cause farmers to fail to meet their obligations with regard to traceability of inputs. If this were to happen, credibility with the end user and regulator would soon be lost. It is therefore important the utility has the ability to model the impact of a proposed application, before it is made, to ensure the application is compliant. Since the implementation of the 1989 regulations, with their requirement for a statutory register, all water companies have set-up some kind of computerised system for recording application details, linked to their laboratory information management systems. However, more and more are finding legacy systems are unable to deal with the requirements of changing legislation.

Service Levels

A biosolids recycling management system should;

  • be able to compare individual biosolids applications against multiple regulatory requirements,
  • be capable of date-stamping changes to regulations in order to monitor compliance in real-time,
  • be linked to a geographical information system (GIS) in order to validate recycling site location and identify sensitive areas to be avoided,
  • have the ability to identify fields available for recycling relative to a biosolids source, allowing minimisation of transport distances and costs,
  • provide graphical display of compliance, soil metal capacity, biosolids quality trends,
  • be used to model the impacts of applications before they are made to ensure compliance is not compromised,
  • allow both standard and ad-hoc reports to be generated from the database by any user,
  • maintain production data from all treatment works,
  • track movements from works, through intermediate storage, to final destination.

    The decision many water companies are facing is whether to re-write their existing software, commission the development of a bespoke system to meet their individual requirements, or to purchase a pre-configured package.

    Rewriting existing software may not be possible because of the language used and the need for hard coding of compliance data. Such systems may also require the use of operating platforms which have become redundant as companies look to combine all systems onto the same architecture. For most this will not be an attractive option. The development of a bespoke system, while virtually guaranteeing the required functionality, is a costly option.

    An off-the-shelf package can be a cost-effective way of obtaining the required functionality. There are relatively few packages available in the UK but they provide a basic functionality which can then be customised. This means the costs of developing the core functionality can be spread over a number of customers. BiosolidsManager which is offered by Salmon is an example of a package solution.

    The software incorporates the basic functionality listed previously and will help ensure compliance with existing regulations – including nitrate vulnerable zone (NVZ) regulations and Ministry of Agriculture, Fisheries and Food (MAFF) codes of good agricultural practice – and can be modified to accommodate additional regulations including the 2001 UK regulations and the amended EC directive. The software can be tailored to individual requirements such as the generation of quality assurance documentation and remote access.

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