Skip to main content

Regional Geothermal Geochemistry Monitoring Programme (REGEMP II)

TR 2007/36

Report: TR 2007/36
Author: Katherine Luketina


Chemical characteristics of geothermal fluids provide useful information on the deep resource, as well as on the nature of heat and mass flow from source to the surface. A geothermal geochemical monitoring programme (REGEMP) for the Waikato region was first developed in 1996 (Huser & Jenkinson, 1996), but for various reasons of budget or staff availability, never implemented until now. This new version of REGEMP, REGEMP II, is adapted from the programme of Huser and Jenkinson, taking account of developments that have occurred in the intervening period in relation to policy development, understanding of the nature of the geothermal resource, and the availability of new methods of geochemical analysis.

In addition to springs in the Taupo volcanic zone, the 1996 programme sampled a limited number of small isolated springs. The 2005 programme has added significantly to the number of isolated springs sampled. These springs are increasingly being used for leisure bathing and in some cases for horticultural uses. It is necessary to sample them to establish a baseline for unused springs, and to monitor effects of several small takes on small geothermal systems. For this reason, all small geothermal systems that have springs or wells that are readily accessible are included in the current programme.

Regional Geothermal Geochemistry Monitoring Programme (REGEMP II)
(257 kb, 36 seconds to download, 56k modem)

Table of contents

Abstract iv
1 Introduction 1
1.1 Monitoring the Waikato regional geothermal resource 1
2 Design of monitoring programme 5
2.1 What do we need to monitor? 5
2.2 Sources of fluid 6
2.3 Important considerations 7
2.4 Schedule of previous work 8
3 Collection and analysis 9
3.1 Analysis of waters 9
3.2 Rationale of analysis of waters 9
3.3 Analysis of gases 10
3.4 Rationale for analysis of gases 10
3.5 Isotope analysis of gases and waters 11
3.6 Rationale for isotope analysis 11
4 Current monitoring programme 12
4.1 Springs and fumaroles to be sampled 12
4.2 Sites 12
4.3 Small geothermal systems - water samples 23
4.4 High temperature geothermal systems - water samples 24
4.5 Fumaroles - gas samples 29
References 31