Once Renewable Natural Gas (RNG) produced from organic matter is put into a regular natural gas pipeline, it mixes in with the fossil gas moving in the same pipe. So a company or business that buys RNG needs to answer "how do we know that this gas is actually RNG?"

The answer is that to use RNG, a customer needs to draw regular natural gas off the pipeline system, then connect a Renewable Natural Gas Attributes (RNG-A) certificate to the gas they are burning in order to know it is RNG.

This means the RNG-A certificates must be rock-solid - they can't be faked, they can't be duplicated, they can't be re-used.

This is where RNG Assurance steps it. We provide assurance that RNG is really RNG. We provide that assurance to gas utilities, to customers, to regulators, and to producers.

Because the voluntary RNG market does not fall under controlling regulation, then RNG producers and purchasers are technically under no obligation to use a third-party validation system. However, a robust and trustworthy compliance system that accurately accounts for RNG production, custody and consumption is the foundation for stable and secure transactions in the volunatry market.

To develop and maintain this trust
- that is the heart of RNG Assurance.

RNG and RNG-A verification follows a Quality Assurance Plan (QAP) that maps the process of verification of gas flow and processing. The QAP is a comprehensive document, and guides the verification process from the initial source of the gas (either a landfill or digester) through the RNG processing/production plant, and terminates at the point of injection into a common-carrier natural gas pipeline.

The QAP may be modified for individual sites to correctly assess and account for technology processes being used that often vary from facility to facility.

Both physical and administrative controls form part of the verification process. Physical controls include inspections and audits of gas flow processing equipment, evaluations of equipment maintenance, calibrations, and review of quality control systems. Inspections occur at the landfill gas wells, condensate removal systems, pipelines, the gas blower system, entry point into the processing plant, points of flow stream diversion, and at the point of final injection into a pipeline. Equipment that controls or measures gas flow is inspected, including valve stations, flowmeters, pressure sensors, thermocouples, and gas chromatography analyses of gas quality to meet pipeline specifications. Finally, process energy consumption records of the energy used to operate the RNG plant itself are reviewed.

Administrative controls include inspection of standard operating procedures and records related to the operation and production of the landfill or digester source as well as the RNG processing/production plant. These include reports of gas volumes produced, maintenance and calibration of gas measuring equipment, plant upset or downtime records, operator certifications, training logs, and source air permit logs indicating flaring or other releases of gas. Because RNG-A are typically decoupled from the gas itself, record keeping of the batch quantities and separation of the RNG and RNG-A must be verified as accurate and consistent.

Certificates that describing batch volumes of RNG-A produced are issued to the producer. Most often these certificates immediately transfers to the contracted buyer. The compliance process also involves auditing certificates issued against process flow records to ensure the accuracy and to address any physical variance related to the certificates.