TITLE:
Colorado Water Watch: Real-Time Groundwater Monitoring for Possible Contamination from Oil and Gas Activities
AUTHORS:
Huishu Li, Ji-Hee Son, Asma Hanif, Jianli Gu, Ashwin Dhanasekar, Kenneth Carlson
KEYWORDS:
CWW, Groundwater Quality, Groundwater Quality Monitoring, Event Detection, CANARY
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.9 No.13,
December
29,
2017
ABSTRACT: Currently, only a few states in the U.S. (e.g. Colorado and Ohio) require
mandatory baseline groundwater sampling from nearby groundwater wells
prior to drilling a new oil or gas well. Colorado is the first state to regulate
groundwater testing before and after drilling, requiring one pre-drilling sample
and two additional post-drilling samples within 6 - 12 months and 5 - 6
years of drilling, respectively. However, the monitoring method is limited to
ex-situ sampling, which offers only a snapshot in time. To overcome the limitations
and increase monitoring effectiveness, a new groundwater monitoring
system, Colorado Water Watch (CWW), was introduced as a decision-making
tool to support the state’s regulatory agency and also to provide real-time
groundwater quality data to both industry and the public. The CWW uses
simple in-situ water quality sensors based on surrogate sensing technology
that employs an event detection system to screen the incoming data in near
real-time. This objective of this study was to improve the understanding of
groundwater quality in Wattenberg field and assess event detection methods.
The data obtained from 5 sites (the earliest monitoring sites in the CWW
network) for 3 years of the regional monitoring network in Wattenberg field
is used to illustrate the background information about groundwater quality
and its changing trend, and make comparisons between two outlier detection
methods, CANARY and simple moving median.