Environment Impact Assessment For Jiangxi Shangrao Sanqingshan Airport Beijing Guohuantiandi Environmental Technology Development Center. Ltd. Oct. 2012 Content


Impact analysis of Environmental Risk



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4.7 Impact analysis of Environmental Risk


4.7.1 Risk Identification

4.7.1.1 Risk link identification


This project mainly includes the flight projects, terminal area engineering, transportation and engineering, air pipe engineering, engineering, meteorology, navigation engineering assistant lighting engineering, power engineering, water supply, rain, sewage works, fire, rescue engineering, heating, cooling system, oil engineering, approach road, supporting pipeline engineering. Analysis of possible environmental risk of facilities for fuel tank area, automobile gas station and sewage treatment plant, the environmental risk of links and affected by the environmental factor see Figure 4-7-1

Figure4-7-1 Environmental risk link and environmental factor relations diagram


(1) Fuel tank area

The new airport depot is located in the terminal area on the west side of oil depot, located 3 blocks 100m3 ground horizontal steel fuel tank, 1 bottom tank of 5m3, comprehensive office building of 100m2, oil equipment library of 20m2, measuring room of 15m2, power distribution room of 20m2, receiving oil and oil shed of 165m2; and equipped with 2 tankers of 20000L.

(2) Gas station

Newly build an automobile gas station in the airport approach entrance, equipped with 4 horizontal buried oil tanks of 25m³, wherein the 2 tanks for the storage of gasoline and another 2 tanks for storage of diesel.

(3) Sewage treatment station

This period plans to build sewage treatment station on the west side of the terminal building with the capacity of 10m3/h and the building area of 50m2.


4.7.1.2 Dangerous substance identification


The hazardous substances related to the airport include aviation kerosene, gasoline and diesel; see Table 10-1-1 for the physicochemical properties and criticality analysis of dangerous materials.

Table 10-1-1 Aviation kerosene physicochemical properties and hazard analysis



Aviation kerosene (data for part use of kerosene)

Physicochemical properties

Mainly by the distillation of crude oil from kerosene fraction obtained by processing of refined petroleum products with light weight, wide fraction type ( boiling point 60-280°C ) and kerosene type ( boiling point 135-280°C ) two kinds big. China's civil aircraft for aviation kerosene by No. 3, jet fuel, kerosene with a larger net calorific value and density, fast combustion, complete combustion, and has good thermal stability and cleanliness, no deposit formation and corrosive products of combustion.

Boiling point

140-240°C

Vapor density

0.8g/cm3

Self-ignition point

224°C

Explosion range

0.7-5.0%

Flash point

No less than 38°C

Crystallizing point

No more than -46°C

Solubility

Insoluble in water, soluble in most organic solvents such as alcohols

Hazard analysis

Health hazard:

Acute poisoning: inhalation of high concentrations of kerosene (aviation kerosene by reference to the material) vapor, often there is excitement, then transferred to inhibit, shown as fatigue, headache, drunkenness, trance, muscle tremors, ataxia ataxia; severe cases, disorientation, delirium, consciousness of fuzzy; vapor can cause eye and respiratory tract irritative symptoms, severe chemical pneumonia. Inhalation liquid kerosene can cause aspiration pneumonia, can occur when severe pulmonary edema caused by ingestion of oral, pharyngeal and gastrointestinal irritation symptoms, can appear with inhalation poisoning the same central nervous system symptoms. Chronic effects: neurasthenia syndrome as primary manifestation, and eye and respiratory tract irritation symptoms, contact dermatitis and dry skin.



Pathways: ingestion, inhalation, contact with skin

Toxicological data: LD50: 36000 mg/kg (rat oral); 7072 mg/kg (rabbit percutaneous); LC50: information

Plant health standards: the former Soviet Union MAC (mg/m3): 300 [upper limit]; Chinese MAC (mg/m3): failure to develop standard.

Environmental harm: harm to the environment; atmospheric pollution.

Storage and transportation conditions

Aviation kerosene tank is to have the fire and explosion technology measures, banning the use of easy to produce the spark machinery equipment and tools, canned should note the velocity (no less than 3m/s), and a grounding device, prevent the accumulation of static electricity to light unloading, handling, packaging and containers to prevent damage.

Analysis of danger level

With reference to occupation exposure toxicants hazards classification (UDC613.632) GB5044-85 aviation kerosene harm degree for IV Slight hazards, which belongs to the level of protection.

Table 10-1-2 Gaoline physicochemical properties and hazard analysis

Product name

Gasoline

Another name

-

English name

gasoline; petrol

Physical and chemical properties

Molecular formula

C5H12-C12H26

(Aliphatic hydrocarbon and hydrocarbon)
Molecular weight

72-170

Melting point

<-60°C

Boiling point

40-200°C

Relative density

0.7-0.79 (water)

Flash point

-50°C

Appearance and smell

Colorless or pale yellow volatile liquid; special odor

Solubility

Insoluble in water; soluble in benzene, carbon disulfide, alcohol and fatty

Stability

Danger


Stabile; risk marker 7 (flammable liquid)

Extremely flammable. Its vapor can form explosive mixtures with air. In case of fire, explosion and combustion heat easily. The oxidant can have severe reaction. The vapor is heavier than air, the lower diffusion to very far place, in case of fire will get back.

Combustion (decomposition) products: carbon monoxide, carbon dioxide.


Toxicological information

Toxicity: low toxicity.

Acute toxicity: LD5067000mg/kg (mice orally); LC50103000mg/m3, 2 hours (mice inhalation)

Pungent: people with eye: 140ppm (8 hours), slight stimulation.

Sub-acute and chronic toxicity: rats inhaled 3g/m3, 12-24 hours/day, 78 day (120 solvent gasoline), showed no symptoms of poisoning. Rats inhaled 2500mg/m3, No. 130 catalytic cracking gasoline, 4 hours/day, 6 day/week, 8 weeks, physical activity reduced capacity, nervous system and vigorous energy change.



Table 10-1-3 Diesel oil physicochemical properties and hazard analysis

Product name

Diesel

Another name

-

English name

Diesel oil

Physical and chemical properties

Molecular formula




Molecular weight

180-280

Melting point

-18°C

Boiling point

282-338°C

Relative density

0.85 (water)

Vapor pressure

4.0kg

Appearance and smell

-

Solubility

Slightly soluble in water

Stability

Danger


In case of fire, heat or into contact with the oxidant, it will cause an explosion. In case of high fever, increased pressure within the container, cracking and explosion risk;

Combustion products: carbon monoxide, carbon dioxide;

The substance is harmful to the environment; do not let their suggestions into the environment. As for water and air pollution, destroy the aquatic respiration system. On seaweed should be given special attention.


Toxicological information

-

(2) Fire accident derivatives

Toxic substances generated by fire accidents of oil tank area, and gas station mainly include CO; see Table 10-1-4 for physicochemical properties and toxicological indexes of CO.

Table 10-1-4 Physical, chemical and toxicological index of CO


Product name

CO

Another name

-

English name

Carbon monoxide

Physical and chemical properties

Molecular formula

CO

Molecular weight

28.01

Melting point

-199.1°C

Boiling point

-191.4°C

Relative density

0.97 (air=1)

Vapor pressure

309kPa/-180°C

Flash point

<-50°C

Ignition temperature

610°C

Explosion limit

Upper limit: 74.2%

Lower limit: 12.5%

Appearance and smell

Colorless and odorless gas.

Solubility

Slightly soluble in water and soluble in ethanol, benzene and most organic solvents

Stability

-

Danger

Health hazards: carbon monoxide in blood and hemoglobin and resulting in tissue hypoxia.

Acute poisoning: Slight poisoning appear have a headache, dizziness, tinnitus, palpitations, nausea, vomiting, weakness; Moderate poisoning in addition to the above symptoms, and skin mucosa was cherry red, rapid pulse, irritability, unsteady gait, shallow to moderate coma.

Environmental harm: harm to the environment, water, soil and atmospheric pollution.

Combustion hazard: This product is flammable.



Toxicological information

Exposure control and personal protection: China MAC (mg/m3): 30; the former Soviet Union MAC (mg/m3): 20

Toxicology: LD50: na; LC50: 2069mg/m3, 4 hours (rat inhalation)



4.7.1.3 Major hazard source identification


According to the Major Hazard Installations for Dangerous Chemicals (GB18218-2009), hazardous material critical quantity and the actual quantity carries on the contrast, see Table 10-1-5. It can be seen from the Table that Shangrao Airport risk unit shall not constitute major risk sources.

Table 10-1-5 Table for Major Hazard Installations



Name of unit

Name of material

Critical quantity (t)

Actual maximum storage capacity (t)

Identification result

Fuel tank area of airport

Aviation kerosene

5000

240

No

Filling station

Gasoline

200

35

No

Diesel oil

5000

42.5

No

4.7.2 Source analysis

4.7.2.1 Risk accident investigation and accident tree analysis of fuel tank area


According to the engineering situation of aviation kerosene oil, physical and chemical properties, as well as surrounding sensitive points characteristics of oil depot, oil depot risk may occur for aviation kerosene leakage, fire and explosion risk, may be influenced by the environmental factors including ambient air, surface water, soil, groundwater and surrounding residents.

(1) Case for fuel tank area risk accidents

See Table 10-2-1 for risk case for oil tank area upon investigation.

Table 10-2-1 Oil depot risk case citation



Time

Site

Cause and impact extent

2002.8.24

Oil tank area of certain airport

Employees in the welding of 2# diesel tank into the orifice rain-proof cover bracket right, exercise of violate the rules and regulations, leading to gas explosion fire, tank to the northeast of tossing around 1.5m, overflow tank diesel engine on fire, resulting in 4 deaths, 2 temporary workers injured, oil scrap

2005.3.19

Shiyan City Bailang Oil Depot

A vehicle with number of C-18146 large tanker, the oil depot in 1 sets to gasoline. When mounted to a half tank bottom, front end weld suddenly open to nearly 20 centimeters long a crack, the instant of time a lot of petrol rapid spray discharge

2006.1.5

Henan Province Gongyi City Second Power Plant

Oil tank leakage accident, the factory pipeline due to cold crack not found in time, causing the tank 12 tons of diesel exhaust, 6 tons of diesel oil into Yiluo River, a tributary of the Yellow River

(2) Statistics of accident type

The case shows that the risk of oil depot safety material constitutes a potential danger. Based on 189 cases of oil depot accidents statistics Table 10-2-2 listed depot accident data statistics.

Table 10-2-2 Statistical table for depot accident classification


Accident type

Oil leakage

Fire and explosion

Mixture of oil

Damage to equipments

Others

Number of accident

85

44

35

19

9

Proportion (%)

45

23

19

10

3

It can be seen from data of Table 9-2-2 that run oil (i.e. the leakage) in fuel tank area occurred in all accidents have the highest proportion (45%), so the tank leakage should be this project fuel tank area accident prevention focus.

(3) Analysis of accident tree of oil tank leakage

It can be known from risk accident statistics of fuel tank area that the oil accident types are mainly of the tank leakage. Analysis of accident tree of storage tank leakage in fuel tank area is as follows:

Figure4-7-2 Analysis of oil tank leakage accident tree

It can be seen from the accident tree that oil tank leakage includes two main aspects of the hardware factors : the tank and pipeline control valve, due to hardware to buy or configuration, the maintenance process may have errors, resulting in the tank accessories, parts and accessories for aging defective operating without norms, thus to cause the tank leakage.

(4) Cause for tank leakage accidents of fuel tank area

Through analysis of the accident tree, further determine tank rupture and leakage of valves of tank leakage causes for the fuel tank area. See Table 10-2-3 for specific analysis.

Table 10-2-3 Anaylsis of cause for tank leakage accidents



Type

Cause Analysis

Tank break

(i) tank aging, external force and the interior of the tank leaks

(ii) by the external extrusion . Mainly include impingement, fission

(iii) tank capacity beyond the prescribed, excessive internal pressure

(iv) under the external environment vibration factors leading to the tank fission, caused by leakage of materials

(v) under the external environment influence by simulated acid rain, the tank from corrosion

(vi) war, natural disasters and other factors caused the tank rupture, leading to leakage of materials

(vii) tank repair, maintenance and the cutting process, illegal operation causes the leakage of materials

Valve leakage

(i) loose valve: for long time, the vibration switch is operated to cause a valve in the affected by external factors easy looseness, causes the stored material leakage

(ii) by the external cause valve damage: is impacted by external force, the natural factors cause the valves broken or destroyed, causing memory leakage

(iii) control valve operating without norms: artificial switch control valve, is not strictly according to the standard operation, on the valve is closed when the tank to transport material

(iv) valves aging, compression fittings aging, too strong, too much to bear pressure, causing the valve loosening or breakage, caused by leakage of materials

(v) other accidents: due to accident, causing the valve failure, caused by leakage of materials

4.7.2.2 Analysis of automobile gas station risk accident investigation and accident tree


The gasoline stored in automobile gas station oil tank is of easy evaporation, flammable, explosive, easy flow diffusion, thermal expansion and easy to generate electrostatic properties; once the vapor concentration to achieve combustion limit, meet the fire combustion or explosion may occur. Possible risk of gas station for oil tank leakage, fire and explosion, may influence the environment there are elements of ambient air, surface water, soil, groundwater and inhabitants.

Analysis of automobile gas station fire accident tree is as follows:



Figure 4-7-3 Analysis of automobile gas station fire accident tree

It can be seen through the accident tree that gas station risk with the fuel tank area risk similar mainly for leakage, fire and explosion, the oil vapor from escaping the main reason for the existence of leakage, fire source will cause fire and explosion risk.

4.7.2.3 Analysis of risk accidents of sewage treatment station


Sewage pollution factor for BOD5, COD, SS, NH3-N and petroleum, once the sewage treatment station failure will lead to exceed the standard waste.

After investigation of wastewater treatment station for management and operation of major accidents and part of irresistible factors, see Table 10-2-4 for the analysis of the cause for the accident.

Table 10-2-4 Analysis of causes for accidents of sewage treatment station

Type

Cause Analysis

Problesm in management and operation

(i) the inlet water temperature and pH value adjustment error, cause microbial death

(ii) of water quantity control is not continuous, causing microbial quantity is not stable, so that the efficiency of sewage treatment unqualified

(iii) sewage treatment station outlet water quality on-line monitoring instrument fault, Unqualified failed to detect that exceed the standard, sewage enters the reservoir

Part force majeure

(i) the storm, resulting in a sewage treatment station intake amount is too large, beyond the sewage treatment station processing ability, making sewage treatment to qualified

(ii) receives the accident caused the water concentration is higher, drainage, sewage treatment station normal processing capacity and efficiency to meet the special requirement of water quality

(iii) due to sewage treatment station water conveyance pipeline, part of the sewage without treatment or treatment without qualified enters the reservoir

It can been seen from the table above that processing station operation failure is mainly due to artificial regulation violations, causing partial process failure or biological bacterial death; water quality is poor and containing inactivated active bacteria microbial substances, causing biological degradation function failure and some factors which can not be avoided.

4.7.3 Determination of maximum credible accident

According to analysis of engineering accident investigation and accident tree, determine the maximum credible accident as the oil storage leakage pool of fuel tank area to have accident. The oil tank of automobile gas station in the project is buried oil tank, probability of risk occurrence is relatively small, and analysis result of fuel tank area can be referred to for environmental risk assessment.

Referring to statistical data of Practical Technology and Method of Environmental Risk Assessment, the probability of oil tank leakage pool of tank area to have accident is 8.7×10-5 times/(years•tank)

4.7.4 Forecast Analysis of Environmental Risk Impact

4.7.4.1 Forecast of tank farm fire accident impact


(1) Source analysis

This evaluation plans to newly build aviation kerosene tank leakage of 100m3 to cause the fire of cofferdam with the area of 534.6m2 (24.3m× 22m). The part without full combustion in the fire after leakage of the oil tank is 20% of leakage combustion losses, and the time for fire accident to generate CO is 1h. See Table 10-4-1 for source strength parameters.

Table 10-4-1 Pollution source intensity of aviation kerosene leaking pool fire accident


Parameters

Unit

Value

Remarks

Carbon content

%

80




Burning rate

kg/(h•m2)

55.11

The whole liquid pool is on fire; maximum rate of combustion

CO generation amount

g/s

3055




Fume height

m

15

With pool fire height as reference

Fire duration

min

60

Fire rescue control time

Cofferdam area

m2

534.6




The formula to calculate the generation rate of CO is as follows:

Q=28/12·V·S·m·20%

=28/12×55.11×534.6×0.8×20%=10999kg/h =3055g/s

In which: molecular formula ratio of 28/12-CO to C;

S-liquid pool area, m2

V-aviation kerosene combustion quality rate, kg/(h•m2)

m-carbon content in aviation kerosene.

(2) Impact forecast

(i) Forecast scheme

Average speed of the regional for years is 1.2m/s, the evaluation selects wind speed of 0.5m/s and 1.2m/s and D & F stability as forecast conditions from the perspective of forecast angle of the impact.

(ii) Forecast result

Under conditions of wind speed at 0.5m/s and 1.2m/s, see Table 10-4-2 and 10-4-3 respectively for forecast result of CO ambient air impact of fire accident of kerosene tank leakage.

Table 10-4-2 CO ground concentration and time forecast under condition of 0.5m/s


Downwind distance (m)

D stability

F stability

Pollutant concentration

(mg/m3)
Duration

(min)


Pollutant concentration

(mg/m3)
Duration

(min)


100

799.0839

33.14

882.9658

33.01

200

246.2977

36.27

506.3228

36.02

400

64.6336

42.55

166.170

42.05

600

28.7104

48.82

77.3350

48.07

800

16.0112

55.09

43.8630

54.1

1000

10.1374

61.37

27.9870

60.12

1200

6.9615

67.64

19.2937

66.14

1400

5.0538

73.91

14.0477

72.17

1600

3.7362

80.19

10.6213

78.19

1800

2.7292

86.46

8.1159

84.22

2000

1.9952

92.73

6.1817

90.24

2200

1.4801

99.01

4.7231

96.26

2400

1.1200

105.28

3.6461

102.29

2600

0.8649

111.55

2.8541

108.31

2800

0.6807

117.83

2.2672

114.34

3000

0.5449

124.10

1.8271

120.36

Table 10-4-3 Estimated CO ground concentration and time forecast under condition of 1.2m/s

Downwind distance (m)

D stability

F stability

Pollutant concentration

(mg/m3)


Duration

(min)


Pollutant concentration

(mg/m3)


Duration

(min)


100

1012.0720

31.31

120.6622

31.26

200

493.6856

32.61

464.0309

32.51

400

148.2316

35.23

308.1111

35.02

600

68.1996

37.84

167.2508

37.53

800

38.8239

40.46

101.0533

40.04

1000

24.9774

43.07

66.8641

42.55

1200

17.3869

45.68

47.2779

45.06

1400

12.7852

48.30

35.1081

47.57

1600

9.7876

50.91

27.0595

50.08

1800

7.7270

53.52

21.4710

52.59

2000

6.2500

56.14

17.4370

55.10

2200

5.1554

58.75

14.4317

57.61

2400

4.3218

61.37

12.1337

60.12

2600

3.6724

63.98

10.3376

62.63

2800

3.1568

66.59

8.9075

65.14

3000

2.7407

69.21

7.7503

67.65

It can be known from forecast result that under the conditions of wind speed at 0.5m/s and 1.2m/s, CO concentration does not exceed standard limit of LC50 concentration (2069mg/m3). The impact under wind speed at 1.2m/s is larger than that under wind speed at 0.5m/s. Under the conditions of D and F stability, see Table 10-4-4 for CO concentration beyond the related index range.

Table 10-4-4 List of CO concentration beyond range of related index under condition of accident



No.

Concentration (mg/m3)

Standard source

Human toxicity reaction

Over-standard distance (m)

D stability

F stability

1

30

GBZ2-2002 workplace harmful factors of occupation exposure limits-standard limit values are consistent with MAC

Short-time contact allowable concentration (15min)

900

1500

2

2069

Environmental Data Handbook for Chemicals Toxicity

LC50, 4hours (rat inhalation)

-

-

3

1700

GBT18664-2002 respiratory protective equipment selection, use and maintenance

Immediately dangerous to life and health

-

-

Under the wind speed of 1.2m/s and F stability conditions, CO concentration does neither exceed standard limit of LC50 concentration ((2069mg/m3)) nor the standard limit of IDLH concentration (1700mg/m3), and the maximum distance over MAC is 1500m.

The sensitive points include 6 residence plots-Xiajia of Tashui, Xujia, Zhangjia, Huangjia Shantou (Tashui Village committee), Hewu and Fangcun, and one school-Tashui Primary School within the range of 1500m around oil storage area of the airport. Under state of accidents, the health of residents and teachers & students may be affected by CO to certain extent. We should remind the surrounding villagers and teachers & students of personal protection. See Figure 4-7-4 for risk impact range diagram.


4.7.4.2 Impact analysis of gas station explosion accidents


With reference to Fire and Explosion Risk Index Assessment Method of Dow Chemical Company (Seventh Edition), determine the fire, explosion radius of influence (actual exposure radius). Make gas station wherein gasoline tank leakage, if leakage is 5m3, the actual exposure radius of fire and explosion:

R=F&EI×0.84×0.3=48.1×0.84×0.3=12.1(m)

F&EI-fire and explosion index

Actual exposure area: S=459.7m2

According to the analysis of forecast result, the project of gas station oil tank fire and explosion accident happens, the effects of radius 12.1m, gas station pump house and office may be affected, and the other protective elements are affected less likely.

In addition, gas station explosion's impact on the environment also includes: the explosion of oil drops to smoke will cause explosion point as the center must be within the range of Landing large fume dust, explosion temperature, pressure, space over the local visibility also will produce apparent change, thus on local atmospheric environment impact.

4.7.5 Countermeasures for environmental risk

4.7.5.1 Countermeasures for risk of fuel tank area and gas station


(1) Countermeasures for materials leakage

See Table 10-5-1 for countermeasures for materials leakage of fuel tank area.

Table 10-5-1 Countermeasures for materials leakage of fuel tank area

Countermeasures for material leakage in oil depot area

(i) in oil storage area and related areas set up monitoring probe, to the surrounding environment of the flammable and explosive gas monitoring at all times, so that in the first time to find material leak accident, and determine the accident

(ii) periodically check the oil storage tank, connecting pipelines and control valves, timely maintenance and replacement of damaged parts of the original, on the part of the components of the maintenance, to reduce the possibility of accidents

(iii) in strict accordance with the fuel storage area to standardize the operation, avoid material storage conditions changed as a result of accidents

(iv) to avoid the fuel storage area of civil construction, in order to reduce the accident resulting in the tank and pipeline valve failure

(v) for tank area were patrolling, prevent the theft destroys the tank, piping, valves and related accessories, causing the accident; in the receiving oil tank valve interface, etc. shall set up warning signs

(vi) upon the occurrence of oil reservoir oil spill, should immediately close all operations of the tank valve, stop fuel delivery, check the oil-water separation tank and tank bottom valve, closing the entrance and exit. In order to prevent the massive oil spill through the oil separation tank into the airport drainage system, should be promptly will reserve oil-absorbing cotton or sediment diffusion overflow oil fixed, to avoid the impact of wastewater treatment station

(2) Countermeasures for fire explosion accidents

The oil depot belongs to first-class fire prevention unit, which will cause threat to the security of residents who are near the oil deport once there is fire or explosion At the same time, the burning of aviation kerosene will emit a large amount of oil fumes, thus to cause pollution to atmospheric environment and soil environment. See Table 10-5-2 for countermeasures for fire and explosion accidents aiming at actual conditions of the project.

Table 10-5-2 Countermeasures for fire explosion accidents

Oil depot area

(i) work area to prohibit all ignition sources (including high heat source)

(ii) set in the work area fire monitoring alarm, convenient in a fire, the first time signal, and take corresponding measures to further expand, avoiding fire

(iii) within the work area is equipped with corresponding fire-fighting equipment, and ensure the quantity and quality of clearance

Automobile gas station

(i) gas station site selection, design, construction and quality of equipment must comply with the relevant national safety regulations

(ii) gas station and storage tanks, piping, breathing valve, safety valve, flame arrester, flange jumper and electrostatic grounding device must be inspected regularly, maintenance, maintain a good working state

(iii) oil, gas must be on-site supervision, in accordance with the rules of operation, to prevent roof fall run oil

(iv) to strengthen the fire management, prevent fire, no miscellaneous personnel in

(v) the production staff to master the operating technology and fire safety management regulations

(3) Water treatment in fire accidents

Fire prevention of airport is Class VI for construction of fire station of 760m2 and configuration of 5 fire cars (main bubble cars, car lighting, fire communication command vehicle for each 1, heavy bubble car for 2).

In order to prevent fire accident water pollution to the surrounding soil and groundwater, it is required to build a fire accident pool. According to Design Guidelines on Emergency Measures against Water Pollution Prevention and Control released by Sinopec Group, the volume of new accident pool is calculated as follows:

Total effective volume of accident storage facilities:



=367m3

Note: respectively calculates for different tank groups or devices within the range of collection system, and takes the maximum value.



-material quantity of a tank group or a set of devices that have accidents within the range of collection system. is calculated according to oil tank of 100m3;

-fire prevention water amount of tank or device that has accidents, m3.

According to Fire Prevention Code of Petro-chemical Enterprise Design GB50160-1992 (1999 Edition), cooling water supply intensity of fire tank and adjacent tank wall is 2L/min·m2, cooling area of fire tank is calculated according to total surface area, and the adjacent tank is calculated according to half a tank surface area. Tank area has 3 oil tanks, all of which are horizontal tanks of 100m3. The area of tank is about 273m2 and fire time is 4h, then the amount of fire water V2=131m3.



-material quantity that can be transferred to other storage or treatment facilities in case of accidents, m3, =0;

-quantity of industry wastewater that must still enter into such collection system in case of accidents, m3, =0;

-rainfall that may enter into such collection system in case of accidents, m3.

V5=qF=136.4m3

q-rainfall intensity, mm; subject to maximum rainfall per day, q=255.2mm;

F-area that may enter into such collection system, cofferdam area F is 534.6m2.

Through the calculation, the project requires new construction of fire accident pool of 367m3 to meet the requirement of water storage capacity. The cofferdam area of airport fuel tank area is 534.6m2 with height of 1.0m and the effective volume of the cofferdam is much higher than that of 367m3, which can meet the requirement of accommodating water for fire accidents. Therefore, the evaluation the evaluation believes that oil depot cofferdam can be used as fire accident pool to ensure water does not enter into the external environment.

4.7.5.2 Countermeasures for abnormal operation of sewage treatment station


The processing capacity of sewage treatment station is 10m3/h, and recovery time for abnormal operation of sewage treatment station is 6h, which discharges sewage of about 15m3. Sewage treatment station abnormal discharge of sewage can be discharged into the regulation pool of sewage treatment station, both to ensure that exceed the standard of sewage into the external environment, and save land and capital.

4.7.6 Environmental Risk Evaluation Conclusions

(1) Under the state of accidents of aviation fuel tank area, and the wind speed conditions of 0.5m/s and 1.2m/s, CO concentration does not exceed the standard limit value of LC50 concentration (2069mg/m3). Under the wind speed of 1.2m/s and F stability conditions, CO concentration does neither exceed standard limit of LC50 concentration ((2069mg/m3)) nor the standard limit of IDLH concentration, and the maximum distance over MAC is 1500m. The sensitive points include 6 residence plots-Xiajia of Tashui, Xujia, Zhangjia, Huangjia Shantou (Tashui Village committee), Hewu and Fangcun, and one school-Tashui Primary School within the range of 1500m around fuel tank area of the airport. Under state of accidents, the health of residents and teachers & students may be affected by CO to certain extent. We should remind the surrounding villagers and teachers & students of personal protection.

(2) The volume of fire accident pool required for the project is 367m3, and the effective volume of cofferdam can meet accommodation requirement of fire accident water. Therefore, the evaluation believes that oil depot cofferdam can be used as fire accident pool to ensure water does not enter into the external environment.

(3) Based on implementation of countermeasures and contingency plans for the above risk, carry out management and operation strictly according to rules and regulations related to the fuel tank area, gas station and sewage treatment station, and the environmental risk level is acceptable.



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    Main page
early stages
overall development
northeastern part
northeast part
strategic position
four provinces