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23rd World Gas Conference, Amsterdam 2006

ADVANTAGE AND HAZARD TO THE ENVIRONMENT FROM CONSTRUCTION AND OPERATION OF UNDERGROUND GAS

STORAGE FACILITIES

N. Vlasenko

Co-authors: S. Khan, A. Arutyunov, G. Akopova

VNIIGAZ, GAZPROM

RUSSIA

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ABSTRACT The paper describes positive and negative aspects o f the basic UGS facilities’ impact on the environment using the results of the study of ecolo gically hazardous factors on the UGS operation areas. On the basis of results of ecological investigation s at Russian underground gas storages that have been recently carried out a comprehensive esti mation of UGS impact on the environment was given and ecological characteristics of surface fuel-consuming equipment and the processes of pollutant distribution from emission s ources were studied. A few natural and technogenic zones with increased normative indices for pollutants related to UGS operation are of limited character. Location of zones with negative ecological effect requires constant ecological monitoring. Recovery of ecosystems and achievement of UGS envir onmental stability are based on a system of effective environmental measures that has been developed on the basis of accumulated research experience. Timely making of recommended environmental, technic al and administrative decisions will eliminate negative impacts and improve ecological r eliability of storages. It is shown that UGS ecological situation in Russia is in general positive and meets safety and reliability targets.

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TABLE OF CONTENTS

1. Introduction 2. Basic concepts 2.1 The goal and methods of study 2.2. Description of facilities under consideration

2.3 Environmental normative-legal support of UGS operation

2.4 Methodological basis for environmental investigation of UGS 3 Results 3.1 Atmospheric air impact 3.2 Soil impact 3.3 Water bodies impact 3.4 Specific environmentally dangerous factors in natural and technogenic systems of UGS 4. Mechanisms of compensation of hazard factors impact on the environment Conclusion References

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1. Introduction

The development of underground gas storage (UGS), being on the rise all over the world, calls for handling arising ecological problems.

Considering the factors impacting the environment in the UGS location zone the following kinds of impact can be distinguished: 1) chemical – bringing various pollutants into environmental objects; 2) mechanical – soil degradation, wastes formation; 3) physical –environmental pollution due to man-caused accidents. In this connection monitoring of natural and man-caused systems at all stages of UGS life cycle is of great importance for enhancing environmental stability and personnel and population safety.

The enhancement of the UGS environmental stability envisages the use of ecologically

oriented technologies and solutions, tactical steps for minimization of man-caused impact on the environment.

The environmental monitoring system must allow for the evaluation of pollutant amount,

inspection and analysis of environmental quality based on physicochemical, biological and other parameters. A general problem of UGS environmental monitoring is solved by a local monitoring of components of the environment and by a regular inspection of technological sites and equipment for revealing possible emission sources.

Investigations оn assessment of UGS environmental and technogenic systems by the results

of ecological survey (control, monitoring, audit) carried out by VNIIGAZ during recent years. The results allow to say that, as a rule, negative factors at UGS objects are of local character and linked to technological equipment.

Environmental control of UGS creation and operation must follow both government and

industrial regulation. [1, 2]. The paper describes positive and negative aspects of the basic UGS facilities’ impact on the

environment, using the results of the study of ecologically hazardous factors in the UGS operation areas. On the basis of investigations, a system of geo-ecological monitoring of natural-anthropogenic media at Gazprom’s UGS objects and timely environmental, engineering and managing decision-making, aimed at the lowering the man-caused impact, was organized. 2. BASIC CONCEPTS 2.1 The goal and methods of study

The main goal (is) - the creation of methodological basis for detection, assessment and lowering the negative impact on the environment and provision of the UGS environmental stability; - systematization of positive and negative factors at stages of UGS construction and operation.

The main tasks include:

• study and evaluation of the conditions of natural and techogenic systems of UGS-

located regions; • development of technical solutions and recommendations on localization or

elimination of contamination factors.

From the one hand, the methods selected for carrying out environmental study at gas storing facilities fall into a classical pattern of environment monitoring, and from the other hand, they consider the specificity of UGS operation (operational cycling and types of equipment).

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The work was based on methods and means of environmental monitoring (EM) of the UGS facilities’ natural-anthropogenic systems:

• strip and field survey; laboratory chemico-analytical work with the use of modern analysis technique and precise equipment;

• data analysis and assessment, • compiling of database for interaction with the elements of vertically integrated system

of computer.

2.2. Description of facilities under consideration Objects of study - major basic UGS facilities of the Unified Gas Supply System, constructed in

aquifers – Kasimovskoye (the largest in the world), Uvyazovskoye, Kaluzhskoye, Shchelkovskoye, and in depleted fields – Stepnovskoye, Yelshanskoye, Severo-Stavropolskoye. (UGS was at stages of construction, operation and technical re-equipment.) Storages are included into the Gazprom’s branched gas transmission and distribution system in order to shave seasonal peaks, to create long-term reserves and to secure export gas supply [3].

A general review of the basic sources of emission of pollutants formed at stages of

construction, normal operation or temporary violations in operation of surface UGS facilities is given in Table 1. 2.3 Environmental normative-legal support of UGS opera tion

Normative-legal documents of the Russian Federation determine the necessity in monitoring the environment at all stages of economical activity implementation. Gazprom’s environmental activity is regulated by a complex of documentation of different legal levels given in diagram (Table 2).

Construction and operation

of UGS surface equipments

Pollutant

Gas

pum

ping

uni

ts

Com

pres

sors

Boi

ler

unit/

F

ire h

eate

r

Fla

re

Ven

t pip

e

Dry

ing

units

Val

ves

Sep

arat

or s

tatio

ns

Sto

ck r

eser

voir

build

ing

tech

nolo

gy/

mot

or tr

ansp

ort

Exhaust gases (Nitrogen, Carbon oxides, etc.)

√√√√

√√√√

√√√√

√√√√

√√√√

Methane

√√√√ √√√√ √√√√ √√√√ √√√√ √√√√ √√√√

Methanol

√√√√ √√√√ √√√√ √√√√

Glycol

√√√√ √√√√ √√√√ √√√√

Lubricating oil

√√√√ √√√√ √√√√ √√√√ √√√√ √√√√

Hydrocarbon condensate

√√√√ √√√√ √√√√

Formation water √√√√ √√√√ √√√√

Table 1 Emission sources of hazard factors in environment

2.4 Methodological basis for environmental investig ation of UGS

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To assess the mechanism of UGS impact on the environment the methodology, which is based on the developed system of environmental investigation, has been used. The methodology was developed on the basis of normative documents, literature and the results of own investigations. The specificity of UGS functioning (combination of field and gas transmission functions) requires a definite approach to organization and performance of a complex environmental monitoring of condition of natural-technogenic systems. An initial moment of monitoring is process equipment, its location in the territory and related to it a character of environmental impact.

The methodological base of investigation can be presented by the following structure: • Monitoring of natural-technogenic systems – components of the environment and the

main emission sources including UGS facilities (fuel-consumed equipment (FCE) located at industrial sites (Table 1).

• Control and measurement in territories (with a network of observation points) under monitoring: industrial, sanitary-protection zones and settlements.

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Table 2. System of legislative environmental activity of Gazprom

• Substantiation and selection of pollution indices orientated to a real situation that

considers the specific features of UGS process • Application of modern methods of chemical analysis and control for determining a

content of priority pollutants in emissions from FCE and the environmental objects • Methods and criteria of UGS environment evaluation. Evaluation of environmental

condition of storage by comparing obtained concentrations of pollutants with norms (maximum permissible concentrations (MPC), approximately permissible concentrations (APC), other limiting indices and level of pollutants in background points)

• Definition, development and acceptance of environmental and design options by computer results.

3 RESULTS 3.1 Atmospheric air impact

In order to determine the UGS facilities’ contribution to the pollution of the bottom atmospheric layer the content of pollutants was determined in the air of industrial zone and settlements.

Constitution of the Russian Federation Federal laws

Decrees of President Government regulation

Normative and instructive -methodical acts of Federal bodies of executive power, firstly specially

authorized state bodies of the Russian Federation i n the field of environment protection

State standards, norms and r ules, other normative documents of environmental character including technical and tec hnological norms on pollutant emissions, maximum permissible emissio ns, discharges,

etc.

State standards and other documents providing accre ditation, uniformity of methods and means of measurement, acc uracy control,

quality of standard samples

Certified measurement methods

Methodical instructions and recommendations for separate aspects of environmental activity

Branch standards, orders, management, normative and metho dical directives of Gazprom

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Under-emission-plume survey with use of mobile stations in the emission sources mainly gas pumping units (GPU) influence zone, at various distances from the source, showed that detected concentrations of pollutants are below the existing in the RF norms.

An excess of nitrogen oxides (NOx) maximum permissible concentration (MPC) was registered

in location areas of some UGS facilities, because of influence of an alien sources or unfavorable meteorological conditions for emissions dissipation (low turbulence in the air) was traced down and there were

Figure 4 illustrates the effect of emissions from such resource on NOx content in the

atmosphere of sanitary-protection zone of Stepnovskoye UGS. The atmosphere’s background state at areas with minimal influence of objects or prior to

exploitation (Uvyazovskoye UGS) was characterized by extremely low concentration of NOx, methane and benz(a)pyrene (BP).

Figure 1 NOx and CO content in atmospheric air in UGS regions

Instrumental measurements and laboratory analyses of NOx (nitrogen oxide /NO/ and nitrogen dioxide/NO2/), carbon oxide /CO/ in the composition of exhaust gases at the UGS gas pumping units have been carried out. In a number of studies specific indicators have been determined – methane, BP, aldehydes and ketones, phenols, petrochemicals.

On the whole, the environmental composition characteristics for all types of units were stable

enough, and in the majority of measurements did not exceed the existed norms and GOST standards.

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Figure 2 NOx and CO content in effluent gases of gascompressor units

3.2 Soil impact

A list of indices studied that can affect soil condition includes: pH; mineralization; a total

content and fractional composition of petroleum products (hydrocarbons: methane, aromatic and naphthenic); methanol and DEG); microelements including heavy metals (HM); specific environmentally dangerous factors, etc.

According to the revealed contents of priority pollutants in the soil of the UGS influence zone,

the level of the soil cover pollution was assessed as low with local sites of pollution. Exceeded levels of this or that pollutant, in particular, “heavy metals” and “petrochemicals (aromatic HC)” are due to poor performance of technological operations, accidental mechanical soil pollutions (for instance, spillage of combustive-lubricating materials, pollution of soil with household rubbish etc.) (Figure 3). Quite often concentrations of these substances are also exceeded at the man-caused background points (distant from UGS’s and other sources influence).

Conducted to date works on soils survey in the UGS influence zone did not reveal significant

impact of UGS emissions on the soils properties.

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Figure 3 Soil pollutants content

3.3 Water bodies impact

The assessment of the condition of water bodies of various types – natural open and closed reservoir, rain water and formation water in the UGS location area – was carried out by the results of studying of physicochemical properties and indexes cited earlier for soil.

Figure 4 illustrates a number of water samples (%) that corresponds MPC for each tested compound or element.

The majority of priority pollutants indexes meet the normative values. Exceeding of maximum permissible concentrations in a number of cases was registered for the total content level of petrochemicals and some aromatic hydrocarbons.

The results prove that the UGS activity influence on the surface waters composition has no evident effect.

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Figure 4 Conformity of pollutant concentrations in water samples to Russian standards

3.4 Specific environmentally dangerous factors in n atural and technogenic systems of UGS

Considering the interest of specialists worldwide to global environmentally dangerous factors we decided to widen an environmental control frame at UGS facilities. Integral evaluation of ecological system condition requires investigation of ubiquitously distributed chemical factors traced in the environment but at the same time having high biological activity. They include polyaromatic HC (PAH), nitro-PAH, dioxins, N-nitrosocompounds, heavy metals and others. These compounds are dangerous for human health and the environment as they have genotoxic, carcinogenic and teratogenic properties.

The novelty of investigation lies in the fact that qualitative and quantitative analysis of water being within UGS region has been carried out for the first time.

Distribution of strong and weak carcinogens as well as non-carcinogenic specimens in samples has been shown for the most studied group of PAH. Generalized data on PAH content in environmental objects of separate UGSs are given in Figure 5.

BP content, an indicator compound of PAH group, being the most stable and active compound, in FCE influent gases depends on a type of equipment. In general, this content is not high (from hundreds to tens of fraction of mcg/m3).

The presence of NOx in effluent gases gives the chance for forming nitro-PAH , some of which have high biological activity, in the process of incomplete burning of fuel. Nitro-PAH found in effluent gases of gas-compressor units includes non-carcinogenic compounds with a content being from tens to hundreds of mcg/m3.

Analysis of dioxine group composition carried out for some soil samples has revealed areas of industrial sites with an interval of marking agent content of group 2,3,7,8 tetrachlordibenzo-para-dioxine from values below MPC in a background point to a slight increase in MPC.

A comparative assessment of carcinogenic N-nitrosocompounds content in soil and water samples with MPC defined for other media has shown their low importance as environmental pollutants.

It was shown that UGS facilities are insufficient sources of environmentally dangerous factors. Single carcinogenic risk criteria for industrial conditions are still under discussion worldwide [4].

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Figure 5. Quantitative distribution of PAH in environmental objects

4. Mechanisms of compensation of hazard factors imp act on the environment

Negative factors impact on the environment during UGS construction and operation is currently compensated by some economic mechanisms. For example, several years ago payments for ecosystem damage within the specified limits and penalties for emission limit exceeding were put in force in Russia for enterprises emitting harmful matters (pollutant emissions, wastes storage) [5]. This measure allows to restrict pollution of the environment.

Selected samples of tariff system for some pollutants (from a list of the indices applied during ecological inspection of UGS facilities) discharged into the air and water by stationary sources are given in Table 3. Payment rates for industrial wastes storage and consumption are given in Table 4.

Payment rate for a ton (rouble/EURO) MPC mg/m3

Type of impact Matter Within permissible rates

Within limits Working area Settlement

NO2 52/1,53 260/7,66 2,0 0,085 NO 35/1,03 175/5,16 - 0,4 CO 0,6/0,01 3,0/0,08 20 5,0 Methane 50/1,47 250/7,37

Emission into atmospheric air

Benz(a)pyrene 2049801/ 60466,106

10249005/ 302330,53 1х10-6 150х10-6

MPC mg/dm3 (fishery) benzene 552/16,28 2760/81,4 0,5 Oil and NP 5110/150,73 27550/812,68 0,05

Nitrate-ion 6,9/0,2 34,5/1,01 40,0 Disposal in water

Nitrite-ion 3444/101,59 17220/507,96 0,08

Table 3 Payment rates for emission/disposal of pollutants

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Type of impact Type of wastes (by class of environmental risk)

Payment rates for disposal of 1 ton of wastes within fixed limits rouble/є)

1 class (very hazard) 1739,2/51,30

2 – « - (highly hazard) 745,4/21,99

3 – « - (moderately hazard) 497/14,66

4 – « - (low-hazard) 248,4/7,32

Wastes

5 – « - (practically are not hazard): extractive industry; processing industry

0,4/0,01 15/0,43 (за 1 м3)

Table 4 Payment rates for industrial and consumption waste disposal

Payment rates for pollutant emissions into the air by stationary and mobile sources are set for

225 matters and for wastes discharged into water are set for 142 elements/compounds. Payment rates for disposal of consumption and industrial wastes consider environmental risk (Table 4). The rates include the coefficients that consider ecological factors and coefficient for special watched territories. The tariffs are reviewed or indexed every year. Conclusion

Long-term practice of construction and exploitation of UGS facilities of the Unified Gas Supply System revealed their advantage and hazard to the environment, which is instrumental in comprehensive and efficient solution of the UGS environmental stability issue in Russia.

The study showed that the most important positive factors providing appropriate

environmental safety of UGS facilities are as follows:

- conformity of UGS operation to environmental regulations and higher social standards; - studying of the background conditions at the stage of UGS designing aimed at

tracking down the environmental impact dynamics; - organization of continuous environmental control of technological equipment and

environmental monitoring in the UGS facilities location area. The results of environmental monitoring are needed for planning and confirming the efficiency of energy and resource-efficient and environmental measures;

- taking of environmentally supported economic management decisions during the development of the environmental impact assessment at all stages of the UGS facility life cycle;

- conducting of UGS reconstruction and revamping; - planning of resource-saving and nature-conservative measures with use of

accumulated environmental experience; - scientific forecasting of expected changes which won’t result in inadmissible

environmental, social, economic and other consequences. Of the existence of negative processes, revealed at UGS during ecological investigations, with

a great deal of confidence, one may speak in the past time since they are removed in accordance with findings and recommendations of investigations in various temporal periods subject to the technical complexity of decisions.

The most typical and in a number of cases inevitable negative factors of the UGS activity,

which may exert influence on the environment, in particular, on the condition of atmospheric air:

- exceeding norms emissions of nitrogen oxides and carbon oxides due to constructive peculiarities of gas pumping units

- influence of alien sources (transboundary transport)

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- unfavorable meteorological conditions preventing emissions dissipation (in individual cases);

soil (local pollutions): - waste disposal - imperfection of technological operations - emergency spillage of petrochemicals - atmospheric precipitations - degradation in the process of UGS exploitation - high background pollution level

water bodies: - storage construction in salt beds - waste disposal within the given limits and waste infringement - ingress of pollutants with rain, melted snow, underground and subsoil waters - dry deposition on water surface and plane washout of polluted soil cover. With a view to restoration of ecosystems, on the basis of the accumulated experience in

environmental investigations a system of efficient nature-conservative measures was elaborated with a possibility to use them in other problematical or ecologically adverse zones. Particular mechanisms for improving UGS facilities from ecological viewpoint are developed normative-methodical documents for organization and conducting of geoecological investigations for UGS in Gazprom. REFERENCES

1. «On protection of the environment”, The Russian Federation Law, 10.01.02. №7-Ф3 2. “On protection of the atmospheric air”. The Federal Law of 04.05.99 № 96 F3 3. B.V. Budzulyak et al. Present state and reserves for providing UGS with environmental safety. Scientific-methodical review. Moscow. IRTs Gazprom, 2002, p. 106. 4. V.V. Hudolei. Carcinogens. Characteristics, behaviour, mechanisms of action. NII Chemistry, St.-Petersburg, GU, 1999, p. 419. 5. “On payment rates for pollutant emissions into the atmospheric air, pollutant discharge into surface and ground waters, disposal and consumption of industrial wastes”. RF Government regulation of 12 July 2003 № 344 with addition of 1.07.2005, № 410.

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List of Tables and Figures Table 1 Emission sources of hazard factors in environment Table 2. System of legislative environmental activity of Gazprom Table 3 Payment rates for emission/disposal of pollutants Table 4 Payment rates for industrial and consumption waste disposal Figure 1 NOx and CO content in atmospheric air in UGS regions Figure 2 NOx and CO content in effluent gases of gascompressor units Figure 3 Soil pollutants content Figure 4 Conformity of pollutant concentrations in water samples to Russian standards Figure 5. Quantitative distribution of PAH in environmental objects