Where do you take the septic sample when you receive a complaint about a malfunctioning sewage system?

• A. NJDEP State-certified lab
• B. Local municipal lab
• C. Private commercial lab
• D. On-site field test

Answer: (A)

When investigating a complaint about a malfunctioning septic system, you need results that are credible for regulatory purposes. Submitting the sample to the NJDEP State-certified laboratory ensures analyses are conducted using approved methods, with proper QA/QC and a documented chain of custody. This makes the results defensible for enforcement actions and corrective actions under the department’s oversight. On-site field tests can provide quick indicators but aren’t acceptable for formal regulatory determinations because they lack the formal accreditation and defensibility. Local municipal or private labs can perform analyses, but only if they are state-certified for the required tests; otherwise their results may not be recognized in the investigation.