New Learnings on Composting Technological Deployment
Alex Newell
Cornerstone Environmental Group, a Tetra Tech Company
Dublin, California
The startup of several facilities recently in the West Coast are good case studiesfor challenges facedand lessons learnedduring start-upof a covered aerated static pile (CASP) composting facility.During facility start-up, various parts and pieces of the system mustbe tested for proper operation and for coordination with the system programming. At the same time, the operation must meet various requirements of the facility permits, which have different requirements depending on the issuing agency (e.g. the Local Enforcement Agency versus the Air Quality Management District).
A challenge arises from an engineering standpoint during theevaluationand review of the recorded data, primarilyused for permit compliance purposes, for proper operation of both the system programming and proper operation of equipmentduring system start-up. System recording intervals are often set at frequencies that do not allow for assessment of proper system response (e.g. daily versus hourly recordings).
To ensure a coordinated startup that would meet permit requirements, some facilities haveimplementeda prestart-up phase prior to commencing full facility operation. This phase offered the ability to evaluate the system functionality while providing training opportunities for the operations team. This allowed for a streamlined review of the system equipment and programmingas opposed to working through issues as they ariseduring full facility operation.
The implementation of a prestart-up phase consisted of data recording at a higher frequency and reducing feedstock intake from designed rates. Higher frequency readings allow the facility to identify both equipment and programming complications while staying in compliance with permits. Reducing daily intake amounts provided flexibility in facility operations while addressing equipment and programming challenges.
Review of programming is an additional challenge that implementing of a prestart-up phase can help to resolve. Complications in programming from a subcontractor or blower vendor can be difficult to detect prior to start-up as system reactions cannot be addressed without feedstock being accepted. Having the program vendor onsite to provide assistance during the prestart-up phase to make real-time changes as they are occurring aids in accelerating this process.
Coordination of and good communication among the various parties (i.e. operator, compliance specialists, design engineer, equipment vendors and programmers) during facility startup was key to a successful startup of the CASP compost facilities. Challenges with equipment, individual parts and overall programming and management of data required both for operation and for compliance were thoroughly reviewed and resolved due to a smart approach to startup.