Research and analysis

Onshore Oil and Gas monitoring: assessing the statistical significance of changes - summary

Published 22 October 2019

1. Chief Scientist’s Group research summary

This project aimed to identify appropriate mathematical methods for analysing environmental data near onshore oil and gas (OOG) sites. These methods could help us to define and describe pre-operational “baseline” data and show how statistically significant changes from baseline levels may be detected.

The potential development of the OOG industry in England has raised a number of controversies and much has been made of the need to understand “baseline” environmental conditions. Although monitoring techniques are well understood, procedures for data analysis, baseline-setting and source attribution are less well established. This study reviews what has been done in other air-quality and groundwater contexts, including existing OOG sites, and recommends procedures for use with OOG activities.

This report can help operators and others to appreciate the factors that should be considered when designing an environmental monitoring programme for the baseline and operational stages of an OOG facility.

1.1 Why was this project needed?

Development of the United Kingdom’s OOG resources is at an important stage. After some years with little activity on the ground, we now have a number of exploratory sites coming forward. Monitoring at such sites must satisfy the need for assessment of permit compliance, but also needs to be sufficiently comprehensive to meet the information needs of local communities and their representatives.

The report identifies statistical methods to accurately describe the condition of the receiving environment prior to any operations on a site. This includes understanding the uncertainty and variability. These are essential to then determine the extent and significance of changes. This can inform both the design of monitoring programmes and the assessment of data. The report also provides advice on how data can be investigated to identify potential causes of change e.g. due to OOG activities or other variations such as natural seasonal changes.

1.2 What did the project involve?

Phase 1 of the project involved a literature review to identify principles for statistical assessment of air quality and groundwater monitoring data. It considered processes and pathways for pollutants, the regulatory context, monitoring techniques, survey design and statistical techniques. Outline advice for survey design and data analysis was developed at this stage.

Phase 2 developed case studies to illustrate how the principles for statistical assessment identified in Phase 1 could be applied to existing air quality and groundwater data sets from the UK.

Phase 3 finalised advice on procedures for survey design and statistical data analysis. It describes how datasets may be analysed using appropriate statistical tests. It identifies tests to determine significance, and indicates how the findings should be interpreted. The advice on procedures also covers signal strengthening and source attribution using statistical techniques.

1.3 Publishing details

This summary relates to information from project SC160020 reported in detail in the following output:

Report:

SC160020

Title:

Onshore Oil and Gas monitoring: assessing the statistical significance of changes

Project manager:

Roger Timmis, Research, Analysis and Evaluation

Research Contractor:

Ricardo Energy & Environment
30 Eastbourne Terrace,
London
W2 6LA,
United Kingdom.

October 2019

This project was funded by the Environment Agency’s Research, Analysis and Evaluation group, which provides scientific knowledge, tools and techniques to enable us to protect people and the environment.

Enquiries: [email protected]

© Environment Agency