Remember, when ISO 14001 speaks of nonconformity, the requirements refer to the nonconformity of a process with respect to the environmental aspects associated with that process. So, you must start with determining and classifying your organization’s environmental aspects and impacts. From there your organization:
Design monitoring activities (water discharge quality, air emissions, amounts of wastes, …);
Develop procedures and instructions to guide behavior.
Now, you can use the risk-based approach. For each of these actions your organization can ask:
What can go wrong?
Is it relevant?
Can we do something to prevent it from happening?
Can we do something to detect if it happens?
Whenever your detection scheme, your control activities, find something wrong from that list you have a nonconformity. Your organization may develop a central procedure to handle all environmental nonconformities or may have rules inserted in each monitoring plan or procedure/instruction about how to handle each specific environmental nonconformity. For example:
What to do when air emission quality is noncompliant with legislation or permit?
What to do when employees are not segregating wastes?