Public Health and Environmental Laboratories

The COVID-19 pandemic highlighted that proactive monitoring of circulating pathogens is important. Wastewater surveillance gained traction in the United States during the pandemic and has become an efficient way to survey community health throughout the country. This type of testing offers unbiased insight into circulating, population-level disease trends and can allow for targeted health decisions. The results from wastewater surveillance are not reliant on people getting tested on their own and additionally, protects people’s privacy, as results cannot be traced back to individuals.

When a person gets sick, with either bacteria or viruses, they can often shed the virus in their feces/stool when they use the bathroom. After flushing the toilet, the virus travels through the sewage system and eventually ends up at a wastewater treatment facility (if their home is connected to a municipal sewer system). The wastewater technicians take a sample of wastewater, before it is treated, and send it to the laboratory. At the laboratory, scientists test the wastewater sample for pathogens and report the data to the Center for Disease Control’s COVID Data Tracker for Wastewater Surveillance. Public health officials can use this data to influence public health decisions within communities such as, increasing mobile testing and vaccination sites. Originally, wastewater testing was used primarily for COVID-19 detection. However as testing capabilities expand, more pathogens can be monitored to better serve communities.

The Wastewater Unit of the Public Health and Environmental Laboratories (PHEL) provides testing for pathogens in wastewater. The Wastewater Unit works closely with the New Jersey Department of Health Communicable Disease Service (CDS), the National Wastewater Surveillance System (NWSS), as well as a variety of wastewater treatment facilities that are actively participating in the program. These treatment plants service thousands of individuals. This provides data for a large proportion of the state of New Jersey population, but additionally, ensures individual and household anonymity. These treatment plants send samples to the New Jersey PHEL twice a week to be tested.

Please refer to our Wastewater Surveillance Monitoring Program Sampling Guide for complete information.

Current Wastewater Sample Submission Guidelines include the following:

• Only facilities that have completed and signed the New Jersey Department of Health (NJDOH) enrollment agreement form can ship samples to PHEL.
• Any facility that would like to learn more about participation in the program can reach out to PHEL.wastewater@doh.nj.gov.
• PHEL provides collection materials and sample transport, all free of charge to participating facilities.

• Once testing is completed, all specimens are properly disposed of following standard biosafety regulations.
• Each sample must be labeled with the pertinent information and be accompanied by a fully completed requisition form.  A completed form will assure that testing can be performed promptly and that results are routed correctly.
• Please inform all persons who package specimens to follow the PHEL packaging instructions for wastewater specimens. Compliance with ALL required packaging instructions is mandatory for testing.

The following list identifies common items which can delay or invalidate testing:

1. Specimens should not be sent to PHEL without the proper enrollment form and organization of sample shipment.
2. Do not freeze samples; wastewater samples must be refrigerated from time of collection to time of testing.
3. Specimens should be contained in a watertight bottle and be placed in a biohazard bag.
4. Do not submit specimens in glass containers, only use the collection supplies provided by PHEL (free-of-charge).
5. Pack the outer surface of a specimen container with sealed coolant packs.
6. Ensure that a fully completed and legible collection form accompanies each specimen and is placed in the SEPARATE sealed waterproof sleeve of the biohazard bag.
7. Samples received without a completed collection form containing all required fields cannot be processed until a completed form is received by PHEL. This will delay testing.
8. Couriers are instructed not to pick up specimens that are improperly packaged.

All persons submitting samples for wastewater testing should be well-informed on proper handling, safety, packaging and shipping, and documentation procedures for wastewater specimens.

Wastewater testing is done exclusively on wastewater samples prior to water treatment. The two types of wastewater samples that are accepted samples at NJPHEL are composite and grab. A composite sample is when multiple samples are taken over the course of a period of time (typically 24 hours) and pooled together. A grab sample is one collection, taken at a single point in time. Composite samples are preferred for this type of testing because it provides an unbiased sample over a longer period of time. The PHEL wastewater unit follows all biosafety regulations related to the disposal of specimen materials. The diagnostic procedure followed is automated nucleic acid extraction followed by digital PCR and analysis.

Nucleic Extraction:

A raw wastewater sample is complex and contains many different viruses, bacteria, solids, and other organic components. A semi-automated extraction platform allows for the efficient extraction of nucleic acids (RNA/DNA) from raw wastewater samples. To test for specific pathogens, the sample needs to be purified to primarily nucleic acids. Laboratory technicians start with about 10 ml of raw wastewater and end up with a final volume of about 100 microliters of sample containing extracted nucleic acids. This final volume is used for testing on a digital PCR platform.

Digital PCR testing:

Polymerase chain reaction (PCR) helps scientists to measure the types and concentrations of pathogens in wastewater samples. Since pathogen levels in wastewater are highly diluted due to the sheer volume of wastewater that travels through a treatment facility, digital PCR (dPCR) is utilized for testing. Specialized primers are added to the sample mix. This highly sensitive approach allows for absolute quantification, ensuring a more reliable measurement of nucleic acid concentration.