Methane is the main component of natural gas and when it is released into the atmosphere, it contributes to climate change. Gas distribution networks are subject to various aggressions and loads that sometimes lead to involuntary leaks. Current measurements show a large variation in leak flow sizes. A previous GERG project called “Development of an Accurate and Consistent Method for Methane Emission Estimation from the Gas Distribution Grid” – MEEM DSO – aimed to develop a pan-European method to estimate gas grid methane emissions.   

This project was launched as a follow up of the MEEM DSO work, in order to gain more knowledge and insight into underground leaks. Led by Kiwa, the project partners aimed to develop an approach for a European set of measurements of underground leakages to be used in a methane emission evaluation method.

In this GERG project, the available set of measurements and the measurement method at that time were analysed, and the model assumptions were validated by a test program of suctions measurement in Apeldoorn. The project was divided in the following phases: 

• Phase 1:  Analysing, planning & recommendation. 

In this part of the project, two controlled leaks in two different types of soil were constructed on the premises of Kiwa technology. The obtained results validated the effect of variations in measurement conditions and provided an accuracy assessment. Furthermore, they identified the reproducibility of the suction measurement method and gave a suction measurement procedure. 

• Phase 2: Coordinated measurement program 

An evaluation of the data obtained from phase 1 was performed and presented in a workshop with all the partners. This was used as a basis for developing technical standards for emission estimates of gas networks. 

This is a step towards enabling stakeholders to access​ a European database of underground leak measurements with joint effort.