Reference      :

 

R1993-3.98

 

Client             :

 

Date                :

 

January 2001

 

For and on behalf of EHS Consultants Limited:

 

Prepared by    :

 

Checked by   :

 

Vivian Chan

Consultant

 

Simeon Cheng

Senior Consultant

 
 



G:\projects\YauTongBay\Decontam\Report\CAP\R1993-3.98

 
TABLE OF CONTENTS

1. BACKGROUND                                                                                                                    

1.1 Introduction                                                                                                             

1.2 Previous Works                                                                                                        

1.3 The Existing Site                                                                                                       

1.4 Site History                                                                                                                

1.5 Scope of Work and Objective                                                                             

2. DETAILED SURVEY                                                                                                             

2.1 Historical Survey                                                                                                   

2.2 Site Inspection                                                                                                          

3. RESULTS                                                                                                                               

3.1 Summary of Historical Survey Results                                                          

3.2 Summary of Observations                                                                                     

3.2.1 On-Site Survey                                                                                                     

3.3 Summary of Survey Results and Choice of Sampling Locations        

3.3.1 YTML Lot No. 2-4                                                                                                  

3.3.2 YTML Lot No. 5 (Figure 1, Photo 1-4)                                                             

3.3.3 YTML Lot No. 6-11 (Figure 2, Photo 5-12)                                                       

3.3.4 YTML Lot No. 12 (Figure 3, Photo 13-16)                                                        

3.3.5 YTML Lot No. 13-14                                                                                              

3.3.6 Government Land (Crown Land)                                                                 

3.3.7 YTML Lot No. 15 (Figure 4, Photo 17-19)                                                        

3.3.8 YTML Lot No. 54 (Figure 5, Photo 20-21)                                                        

3.3.9 YTML Lot No. 19-21 (Figure 6, Photo 22-28)                                                   

3.3.10 YTML Lot No. 22A/22B (Figure 7, Photo 29-31)                                             

3.3.11 YTML Lot No. 22RP (Figure 7, Photo 32-36)                                                  

3.3.12 YTML Lot No. 23-24 (Photo 32-36)                                                                   

3.3.13 YTML Lot No. 25 (Inaccessible, Photo 37)                                                 

3.3.14 YTML Lot No. 26 (Inaccessible, Photo 38)                                                 

3.3.15 YTML Lot No. 27 (Inaccessible, Photo 39-40)                                             

3.3.16 YTML Lot No. 28 (Figure 8, Photo 41-47)                                                      

3.3.17 YTML Lot No. 29 (Photo 48-51)                                                                        

3.3.18 YTML Lot No. 30-31 (Photo 92-94 )                                                                  

3.3.19 YTML Lot No. 32-33 (Figure 9, Photo 52-61)                                                 

3.3.20 YTML Lot No. 34 (Photo 62-63)                                                                        

3.3.21 YTML Lot No. 35 (Figure 10, Photo 64-68)                                                    

3.3.22 YTML Lot No. 36-37 (Figure 11, Photo 69-77)                                                

3.3.23 YTML Lot No. 38 (Figure 12, Photo 78)                                                         

3.3.24 YTML Lot No. 41-43 (Figure 13, Photo 79-86)                                               

3.3.25 YTML Lot No. 44 (Figure 14, Photo 87-89)                                                    

3.3.26 YTML Lot No. 45-46 (Figure 15, Photo 90-91)                                               

3.3.27 YTML Lot No. 73-74 (Photo 95-97)                                                                   

3.3.28 Salt Water Pumping Station (Figure 16, Photo 98 to 100)                   

3.3.29 Ice & Cold Storage Factory (Figure 17, Photo 101)                              

3.3.30 Gas Pigging Station (Figure 18, Photo 102)                                              

3.3.31 Maintenance Depot (Figure 19, Photo 103 to 106)                                  

3.4 Summary of Site Information                                                                           

3.5 Inaccessible lots                                                                                                   

4. DISCUSSION AND RECOMMENDATION FOR DETAILED SITE INVESTIGATION        

4.1 Site Investigation Sampling Locations                                                        

5. METHODOLOGY OF DETAILED SITE INVESTIGATION                                                 

5.1 Terrestrial Soil Sampling Specification                                                    

5.2 Laboratory analysis                                                                                            

5.3 Precautions Against Pollution                                                                      

5.4 Clean up                                                                                                                     

5.5 Reinstatement                                                                                                         

5.6 Reporting                                                                                                                  

6. TECHNICAL SPECIFICATIONS                                                                                         

6.1 Soil and Groundwater Sampling and Analysis                                          

6.1.1 Soil Sampling Methodology                                                                        

6.1.2 Groundwater Sampling Methodology                                                     

6.1.3 Labelling, Transportation and Storage of Samples                           

6.1.4 Flushing Medium                                                                                               

6.1.5 Safety measures                                                                                               

7. FURTHER WORKS                                                                                                             

 

LIST OF TABLES

Table 2-1 Historical Survey                                                                                                                                         

Table 3-1 Response from Historical Survey                                                                                                              

Table 3-2 Historical Landuse of the Yau Tong Marine Lots                                                                                    

Table 3-3  Site Observations on Marine Lots Concerned with Potential Land Contamination                        

Table 3-4 Summary of Site Information                                                                                                                  

Table 3-5 Description of Inaccessible Sites                                                                                                            

Table 3-6 Current Operational Status of Sites that Require Soil Sampling                                                          

 

 

LIST OF FIGURES

Figure 1-1 Yau Tong Bay Area and its Vicinity (YTML numbers as marked)                                                         

Figure 4-1 Locations of Soil and Groundwater Sampling Points (detail sampling points are shown in Appendix IV)                                                                                                                                                                  

 

 

LIST OF APPENDICES

APPENDIX I   Industrial Activities and Possible Contaminants Identified during the Preliminary Land Contamination Assessment

APPENDIX II   Responses from Various Parties on Site Historical Survey

APPENDIX III Outline Development Plan (1991)

APPENDIX IV Photographs and Layout Plan for Sites Suspected to Suffer from Land Contamination

APPENDIX V   Letter from Project Geotechnical Consultant Explaining Problems Encountered with Marine Mud Sampling

 


1.              background

1.1            Introduction

Future redevelopment of the Yau Tong Bay area (the Site) is proposed by developers and the existing operations shall be removed from the site.  Substantial reclamation should be required for the project. In accordance to the Environmental Impact Assessment (EIA) ordinance procedure for a designated project, an application for a study brief was submitted to EPD in August 1998 for the proposed reclamation works. The study brief issued by EPD in October 1998 (Brief no.: ESB-0010/1998) stated that a land contamination impact assessment should be conducted as part of the EIA study.

EHS Consultants Limited has been appointed by the developer of the Site to prepare this Contamination Assessment Plan (CAP) in accordance to the EIA study brief, which outlines the strategy, methodologies and extent of work required to establish the profile of land condition at the Site.

 

1.2            Previous Works

A walk through site survey for a preliminary land contamination assessment was conducted by the Consultant in August 1998 to form part of the rezoning application of the subject site, with an aim to identify all possible source of land contamination within the site and justify the need for a detailed assessment. The results of this preliminary assessment are summarised in Appendix I for reference only.

 

1.3            The Existing Site

The Site is north- and east- bounded by Cha Kwo Ling Road, south-bounded by Ko Fai Road, and west-bounded by the future Western Coast Road.  It is located immediately to the north of the Yau Tong Industrial Area.  The Yau Tong Bay area and its vicinity is shown in Figure 1-1 with the Yau Tong Marine Lot (YTML) numbers for each lot as marked.

The main types of operations at the Site were ship building and repair, sawmills and timber yards. Subsequent to the moving out or closing down of the original operations, the lots had been occupied by other operations, e.g. concrete batching plants, car repair workshops, construction storage and distribution, etc..  Some of the sites had been vacated while some are in operation. Those operating industries ranged from motor repair, ship repair, to concrete batching, godowns, car parking and timber factories.


Figure 1-1        Yau Tong Bay Area and its Vicinity (YTML numbers as marked)


1.4            Site History

The existing Yau Tong Bay area comprises of Yau Tong Marine Lots (YTMLs), other private lots and Government Land Allocations.  The existing operations are not representative of the site history as land use at these sites have changed over the years. The majority of the YTMLs have been operating as shipbuilding, sawmills and timber yards since the late 1950s, in accordance with the Government Leases conditions. The history of these marine lots, in particular their usages, are of crucial importance to the land conditions. Information regarding the history of these sites was obtained from various sources including governmental departments and published information such as the Outline Development Plan for the Yau Tong area.

 

1.5            Scope of Work and Objective

The scope of this study is to confirm locations of potential land contamination by means of historical survey and on-site visual inspections including interviews with the Site’s staff who were available. Upon confirmation of suspected land contamination, site investigation (sampling) locations and parameters for soil/groundwater analysis would be proposed. The analysis results from the sampling works will form a basis on determining whether the land is classified as contaminated and land remediation strategies derived in accordance to the type and extend of contamination, if so required.

This CAP provides necessary guidelines for a quantitative land contamination assessment including sampling methods and analysis of samples taken at areas that were potentially contaminated.


2.             Detailed Survey

2.1            Historical Survey

The concerned Yau Tong Marine Lots included a variety of existing uses comprising shipyards, sawmills, timber factories, concrete batching, motor repairs, etc. Some of these operations are expected to cause minimal contamination to land due to the nature of the operations. As land contamination is an on-going process, a historical survey on the previous land uses is deemed necessary. A number of information sources such as existing owners and various governmental departments were approached in attempt to secure information pertaining to previous land uses. They are listed under Table 2-1 below:

Table 2-1          Historical Survey

Concerned parties

Information

Existing land owners, Client

Operation details, previous landuse, land search

Lands Department, District Lands Office, Kowloon East

Contaminating land uses, illegal land uses

Lands Department, Lease Enforcement Unit

Contaminating land uses, illegal land uses

Lands Department, Task Force (Black Spots)

Spillage accidents, uncontrolled or illegal dumping areas

Fire Services Department, Management Section

Spill / Fire Incident Report

Land Department

Aerial Photographs

Planning Department

Outline Development Plan

Environmental Protection Department, Local Control Office, Kowloon East

Licence (Chemical Waste Producer)

2.2            Site Inspection

“Walk-through” site surveys arranged through the Client (Main Wealth Co. Ltd.) were carried out on 3rd November1998, 18th November 1998, 5th December 1998, 24th December 1998 and 26th January 1999. Visual inspection for potential land contaminating sources was conducted for every accessible lots.

The site inspections were carried out with the aim of identifying locations of suspected land contamination. These include stains, discoloration, and detection of odour in soil. Special attention was paid to areas where potentially contaminating operations had taken place. For sites which past operations were known, it was possible to identify “hot spots” where operations were likely to have caused contamination. For vacated sites, especially those which buildings were already demolished, the visual inspection coupled with historical search of its previous uses were used to determine whether land contamination was likely.

The site inspection also covered storage areas of hazardous materials and hazardous waste that could potentially contaminate the soil strata.

3.              Results

3.1            Summary of Historical Survey Results

The following is a summary of the response from each of the parties as tabulated under Table 3-1 above:

Table 3-1          Response from Historical Survey

Concerned parties

Response / Comment

Existing land owners, Client

History of tenancy and uses

Lands Department, District Lands Office, Kowloon East

Cannot provide information (Refer to Appendix II)

Lands Department, Lease Enforcement Unit

Pending

Lands Department, Task Force (Black Spots)

Cannot provide information (Refer to Appendix II)

Fire Services Department, Management Section

Pending

Aerial Photos

Aerial photos for the year 1973, 1978, 1983, 1988, 1993 and 1998 were inspected

Planning Department

Outline Development Plan (ODP) of 1991 obtained

Environmental Protection Department, Waste and Water Management Group, 25/F Southorn Centre

YTML 2-4 and 6-11 are currently registered as chemical waste producer with the EPD.

 

Requests and responses from those parties which written request were required are enclosed in Appendix II for reference.

 

Table 3-2 below outlines the historical landuse of the concerned Yau Tong Marine Lots. As all historical information are based on Marine Lots numbers, the rest of the report shall be referenced to the YTML (Yau Tong Marine Lots) numbers.


Table 3-2          Historical Landuse of the Yau Tong Marine Lots

Marine Lot Number

Uses/ Land Contamination Source

Land Contamination Suspected

2-4

Ship repair with jetty (1973 to 1998) d

Marine project and ship repair- registered chemical waste producer (As of 1st May 98) a

Shipyard/ sawmill/ timber yard b

ü

5

Shipyard/ sawmill/ timber yard b

ü

6-11

Ship repair with jetty (1973 to 1998) d

Shipbuilding and ship repair - registered chemical waste producer (As of 1st May 98) a

ü

12

Timber factory (1971 to 1974) c

Timber factory with floating stock in the bay area (1983 to 1993) d Shipyard/ sawmill/ timber yard b

Currently, partially used as lorry repair

ü

13-14

Storage or unknown operation (1973 to 1993)

Storage and packaging (1987) c

Concrete batching plant (1993) d

Vacant (1998) d

Concrete Mixing b

x

15

Ship repair (1973) d

Unknown operation with scattered equipment on the ground, suspected ship repair (1978 to 1993) d

Vacant (1987) c

Vacant,  colour photo shows oil stained ground (1998) d

Machinery workshop b

ü

54

Ship repair with jetty to the west of the lot (1973 to 1988) d

Vacant (1991) b

Storage - jetty reclaimed (1993 to 1998) d

Storage of non-dangerous goods: building materials (1997) c

ü

19-20

Shipyard (1965 to 1967) c

Rented to Rediffusion TV Ltd. of non-industrial operation (1976 to 1982) c

Rented to Wong Kwok Kuen Trading of non-industrial operation (1983 to 1987) c

Unknown operation d

ü

21

Vacant (1971 to 1973) c

Covered workshop at street side, car repair (1993) d

Storage and car repair b

ü

22A

Workshop or covered storage (1973 to 1978) d

Vacant (1980)  c

Storage of dry goods (1983 to 1988) b

Vacant (1991) b

Currently haphazard car parking area

ü

22B

Workshop or covered storage of dry goods (1973 to 1978) d

Vacant (1991) b

Currently haphazard car parking area

ü

22RP

Workshop or covered storage (1973 to 1978) d

Timber/ storage (1973 to 1998) c

Shipyard/ sawmill/ timber yard b

Currently building materials (sand and rubbles mainly) transfer station

ü

23-24

Shipyard/ sawmill/ timber yard b

Timber factory with floating stock in the bay area (1973 to 1993) d

Currently building materials (sand and rubbles mainly) transfer station

x

25

Timber factory with floating stock in the bay area (1973 to 1993) d Shipyard/ sawmill/ timber yard b

Currently timber yard

x

26

Timber factory with floating stock in the bay area (1973 to 1993) d Shipyard/ sawmill/ timber yard b

Currently storage of dry goods

x

27

Timber factory with floating stock in the bay area (1973 to 1993) d

Shipyard/ sawmill/ timber yard b

Currently timber yard

x

28

Timber factory with floating stock in the bay area (1973 to 1993) d Car Repair (1993 to present) c

Shipyard/ sawmill/ timber yard b

Timber Factory c

ü

29

Timber factory with floating stock in the bay area (1973 to 1993) d

Shipyard/ sawmill/ timber yard b

x

30-31

Sawmill (1978 to 1982) c

Vacant (1991) b

x

32-33

Ship repair with jetty at the corner, repair work took place at the centre

of the lot (1973) d

Sawmill purpose (1977 to 1986) c

Mainly storage, except covered workshop at street side suspected for car repair works. (1978 to 1998) d

Storage (1991) b

ü

34

Freight station (1991) b

Storage (1997) c

x

35

Machinery workshop (1991) b

ü

36-37

Timber yard with floating stock in the bay area (1973 to 1983) d

Ship/ machinery repair - dissembled parts and equipment scatter around the site and colour photo of 1998 shows oil stained ground (1988 to 1998) d

Shipyard/ sawmill/ timber yard (1991) b

ü

38

Ship repair with two jetties on the sides (1973) d

Vacant (1991) b

ü

41-43

Jetty on east and west side of the lot (1978 to 1983) d

Active  ship repair works on ground and at jetty in 1988. The lot in front of the workshop was covered with repair equipment, structures, ships under repair and cane for lifting heavy equipment. (1988) d

Structures and cane removed, left behind the main workshop.  Jetty to the west reclaimed.  Repair works in front of the workshop and at jetty. (1993) d

Site under demolition (1998) d

Shipyard/ sawmill/ timber yard b

ü

44

Tenancy to Concrete Co. (since 1993) c, d

Shipyard/ sawmill/ timber yard b

ü

45-46

Ship repair with jetty on Lot 45 (1973 to 1988) d

Tenancy to Concrete Co. (since 1992) c

Concrete batching plant (1993) d

Shipyard/ sawmill/ timber yard b

ü

73-74

Industrial building b

Storage and loading port for kaolin extracted from the nearby kaolin mine (1969 to 1977) d

Vacated (1980) d

Industrial building (since 1983) d

x

Salt Water Pumping Station

Salt water pumping station b

Storage and loading port for kaolin extracted from the nearby kaolin mine (1969 to 1983) d

Vacated  (1990) d

Existing salt water pumping station under construction (1989) d

Salt water pumping station (1990) d

ü

Ice  & Cold Storage Factory

Ice  & cold storage factory b

Storage and loading port for kaolin extracted from the nearby kaolin mine (1969 to 1977) d

Ice and cold storage factory (since 1980) d

x

Gas Pigging Station

Pigging station b

Storage and loading port for kaolin extracted from the nearby kaolin mine (1969 to 1983) d

Covered storage or workshop of unknown operation (1989 to 1990) d

Gas pigging station (since 1991) d

ü

Maintenance Depot

Proposed transfer station b

 

ü

Source of information:

a - Environmental Protection Department (Local Control Office - East Kowloon).

b - Information from Outline Development Plan dated 19 July 1991 as shown in Appendix III.

c - Tenancy record from the Client.

d - Aerial Photos from Lands Department for the year 1973 to 1998.

The above table outlined the various landuses of the Yau Tong Marine Lots from available information. Amongst these uses, some of the lots are not expected to cause noticeable land contamination. These are indicated by an “x” in the adjacent box of the respective marine lot. Those operations that might have caused land contamination are marked with a “ü”.

3.2            Summary of Observations

3.2.1     On-Site Survey

Existing operation at the  Yau Tomg Marine Lots are by and large unchanged since the preliminary site survey conducted in August 1998.  Hence the observations as reported in Appendix I are still considered valid.  In addition, it was noticed the for some of the sites, crushed stones are used for floor covering, which allows contaminants to seep through easily and make direct contact with the soil content. The major contaminants identified were the oil products containing petroleum hydrocarbon and heavy metals which could have leaked or dripped onto the ground during repair works. From the nature of the operations, the ship repair and maintenance workshops and the car repair workshops were identified as major areas requiring detailed site investigation.

Table 3-3 below summarises the on-site observations of each of the marine lots concerned with potential land contamination, i.e., those marked with a “ü’ in Table 3-2.

Figures enclosed in Appendix IV shows the layout of the sites suspected to suffer from land contamination and the sampling locations. Operations within each marine lot that have had the potential of causing land contamination are indicated on the plans. Sampling locations were chosen to target the potential land contamination from these operations. These should form “hot spots” for the detailed site investigation which soil/ground water samples will be taken (refer to following sections for detail). For the sites which previous landuse suggested possible contamination but lacking in details of its operation, selection of site investigation location shall rely on site inspection. Guidelines for SI sampling as stipulated in “Practice Note for Professional Persons for Contaminated Land Assessment and Remediation, ProPECC PN 3/94” were used to determine the extend of SI required. The grids to determine sampling locations were drawn at locations of “hot  spots” for land contamination only and hence do not necessarily cover the entire sites. Some sites have within themselves homogeneous nature of operations. For instance, motor repair stores utilises the whole site for the same type of servicing. For these sites, considering the constraints of existing operations, SI numbers are reduced to a minimum which results will be extrapolated for the whole site. The corresponding remedial methodology will take into account this limitation and where appropriate, additional samplings will be taken at the remedial stage to ascertain the integrity of the land condition. Photographs showing the existing condition of the sites are also included in Appendix IV along with each site plan for reference.


Table 3-3          Site Observations on Marine Lots Concerned with Potential Land Contamination

Marine Lot Number

Observations

Reference Figure in Appendix IV

2-4

·Private lot, inaccessible by the consultant.

-

5

·Ship repair workshop.

1

6-11

·Ship repair inside the workshop and at the jetty. 

·Underground fuel tank exist, but not in use for the past 20 years according to the current operator.

·Strong pungent smell of petroleum product noticed inside and outside of the workshop.

·Land contamination suspected from the past 30 year’s operation.

2

12

·Currently, partially used as lorry repair

3

15

·Currently vacated.

·Ground covered with concrete.

4

54

·Currently occupied by building material distributor for storage of materials such as sand, bricks, bags of cement. 

·Former covered ship repair workshop used for storage.

5

19-20

·Currently building materials (sand and rubbles mainly) transfer station

6

21

·Lot used for storage and parking. 

·A car repair ramp in the lot, at the location of the demolished structure. 

·Previous car repair work had taken place and suspected for land contamination, although no physical evidence observed.

6

22A

·Currently haphazard car parking area

7

22B

·Currently haphazard car parking area

7

22RP

·Currently building materials (sand and rubbles mainly) transfer station

7

28

·Former timber workshop occupied by car servicing and repair workshop. 

·Floor covered with concrete, but mostly cracked and bare ground being exposed. 

·Lubrication and engine oil dripping and seeping into the ground.

·Body painting for damaged vehicle carried out and paint sprayed onto the ground occasionally.

·Strong smell of paint, gasoline and other petroleum product noticed.

·Top soil recovered found to contain oil and petroleum by visual inspection and smelling.

·Land suspected to suffer from contamination.

8

32-33

·Structure used for car repair, but not suspected for land contamination. Rest of the lot used for vehicle parking.

9

35

·Vacated structure.

·Entire lot covered with concrete.

·Previous operations should be carried out inside the buildings.

·No sign of land contamination observed.

10

36-37

·Machine repair workshop in operation, dissembled parts and equipment scattered around. 

·Engine oil dripping and seeping into the unpaved ground. 

·Top soil recovered found to contain oil and petroleum by visual inspection and smelling.

·Strong evidence of land contamination inside workshop as well as at the uncovered storage area.

11

38

·Vacated lot and structure.

12

41-43

·Existing building demolishing, jetty still exist, but no ship repair operation anymore.

·Ground uncovered, hence subject to land contamination from previous ship repair works.

13

44

·Machine repair workshop in operation.

14

45-46

·Concrete batching plant in operation.

15

73-74

·Existing industrial building mainly as godown and offices

·Two levels of underground carparks

-

Salt Water Pumping Station

·Salt water pumping station operated by the Water Supplies Department

·Industrial site in operation

16

Ice & Cold Storage Factory

·Ice producing factory and supplies

·Industrial site in operation

17

Gas Pigging Station

·Exposed gas pipes connected to underground gas pipe network, otherwise vacated site

18

Maintenance Depot

·Storage of construction materials

·Two engine oil storage tanks on bare ground, which

19

Although some of these sites present no signs of contamination, the historical land use has suggested a possibility of land contamination.  It is hence considered necessary for SI to be carried out at these sites strategically.

3.3            Summary of Survey Results and Choice of Sampling Locations

Information on land contamination for each site was summarised below along with descriptions on the proposed sampling points for each site.  Please note that the marine lot numbers are not in numerical order as they are not arranged as such. The following paragraphs were arranged with the sequence of marine lots from one end to the other in their actual order.

Certain sites were identified to be non-contaminated through information available. A description for these sites were also included.

Photographs for each of the sites can be found in Appendix IV of this report. Figures showing the layout of the sites which require further sampling when accessible are also contained in the same appendix.

 

3.3.1     YTML Lot No. 2-4

This site was inaccessible to the consultant during the site surveys, therefore all information pertaining to the lot were obtained form historical records. In accordance to aerial photos from 1973 to 1998, the site was used for ship repair purpose ever since built. The ownership of this site has not been confirmed and hence site inspection was not possible for this site. Since access to the lot can not be granted, sampling locations, whether necessary or not, will not be proposed for this lot at this stage.

Site inspection and possible site investigation (sampling) works for this site shall be conducted when access to the site is available.

 

3.3.2     YTML Lot No. 5 (Figure 1, Photo 1-4)

A vacated structure formerly used as ship repair workshop now sits on the site. Ship repair works were believed to have performed at the jetty attached to the lot and inside the workshop as shown on the aerial photo. The previous jetty area has been filled to level with the rest of the site, but no record could be found to indicate when. From the tools and materials left behind, it was suspected that the site has been used as furniture repair of some sort but no record could be located as confirmation.

 

Visual inspection has found no signs of contamination and there is no storage of potentially land contaminating substances. Three sampling points (T5A to T5C) were proposed to cover both the previous workshop area and the jetty area.

 

3.3.3     YTML Lot No. 6-11 (Figure 2, Photo 5-12)

According to the current operators on-site, an obsolete underground storage tank exists at the land area near the sea as indicated in Figure 2. The tank was believed to be storage for heavy oil for ships’ fuel refill. There are also oil stains around the area but were believed to be from spills from transportation of diesel oil rather than leakage from the underground storage tanks. (Photo 6) A sampling points (T6L) had been selected to cover the stained location.  Smell of fuel oil could be detected near the underground storage tank area. Also according to the current operators, the underground storage tank has been obsolete for more than 20 years, but this information could not be confirmed. Sampling point T6I, T6H and T6J were selected to cover the approximate location of the underground fuel tank. The decommissioning of the underground storage tank shall be included as part of the land remediation plan.  As the exact location of the underground storage tank can not be confirmed at the present stage, further soil sampling shall required after the decommission of the tank, subject to the information obtained from the decommissioning process and the soil sampling results obtained from the current land contamination assessment exercise. Decommissioning of the storage tank, further soil sampling and any necessary soil remediation works shall be completed prior to the commission of the construction.

There are also storage drums scattered mainly in the workshop area. Storage drums were also found haphazardly placed across the site (Photo9). T6A, B, E, F, G, and K shall be taken at the storage and working areas in the three workshops.  Furthermore there are three lines of existing jetty (in use at the time of the site survey) to the south-west of the site (Photo 7) and one existing jetty (obsolete) to the north-east of the site (Photo 8). The main ship repair works were mainly carried out at the jetty areas which could lead to contamination of heavy metals and Tributyl Tin. For the set of three parallel jetty, only one line of jetty will be sampled initially. Should the sample analysis results be unreasonable or deviate largely from the expected results, or if the results are in doubt, further samples will be carried out at the other two lines of jetty to ascertain whether the jetty areas were indeed contaminated. As marine mud sample near the jetty cannot be taken, one sample as near the end of the jetty towards the seaside as possible should be taken to ascertain whether there are contaminants washed out towards the marine area.  Sampling at the residential part of the site (to the left upon entrance will not be sampled as their past uses were all non-contaminating.

            A total number of fourteen samples were proposed for this site.

 

3.3.4     YTML Lot No. 12 (Figure 3, Photo 13-16)

The site history records revealed that this site has always been a timber factory since 1973. However, there is a motor (cement lorries) repair area at this site but was observed to be not always in use. Of the site inspections carried out, it was observed that maintenance works for cement lorries were sometimes carried out. The repair area is a sub-surface area facility for maintenance of the bottom of the lorries. Hence we conclude that the repair area is fixed and localised. Two petroleum product storage areas were observed, one near the entrance alongside with two emergency electricity generators (Photo 15) and another along the same side of the site near the shore area.  There are oil stains observed at each of these locations (Photo 16). Three sampling locations were proposed : one at the petroleum storage/emergency generators location (T12A), one the motor repair area (T12B) and one at the second petroleum storage area (T12C).

 

3.3.5     YTML Lot No. 13-14

Aerials photographs have shown that this site has been used mainly for storage. Since 1993, the site has been converted to a concrete batching plant which is a non-land contaminating process. This site is vacant at the time of the site survey and the visual inspections has revealed no physical signs of contamination. The site was vacant and no new activities was observed during the site investigation.

As there is no suspicion of site contamination, no further site investigation works were proposed for this site.

 

3.3.6     Government Land (Crown Land)

The piece of land was previously classified as “Crown Land”, which is now “government land”. As the land ownership is still at the government, this piece of land will not be considered at this stage. However, once the land’s ownership status has been converted to the developer, site investigation will be conducted.

3.3.7     YTML Lot No. 15 (Figure 4, Photo 17-19)

            This marine lot was originally used as ship repair. However, from the site tenancy record, it has been vacated since 1987 and unknown operations had been carried out during that period. Although the on-site investigation does not reveal any physical signs of contamination, the latest aerial photograph available does shows a colour change thought to be staining of engine oil near the half of the site closer to the sea side. The staining area was about 10m2. Although this staining observed from the aerial photographs can no longer be found on site, two of the sampling points (T15B,C) will nevertheless be taken at the area of staining which was perceived as a hot spot for land contamination. Although there is no site operation at this site, the site history record is not clear enough to ascertain the absent of land contamination. Hence, three sampling points (T15A-T15C) were proposed to ascertain the land condition of this site.

This site is fully vacated and is accessible for sampling.

 

3.3.8     YTML Lot No. 54 (Figure 5, Photo 20-21)

This site has a jetty which has been filled and used as storage area since 1988. Although this part of the site has been stagnant for over 10 years and that there has been no evidence of land contaminating operations at this area since the reclamation of the jetty, there could still be contaminants such as heavy metals from previous land contaminating activities. Hence sampling points at this filled jetty has been proposed. The other half of the site was previously a ship repair workshop which is currently used for storage. Six sampling points were proposed to cover this area of a former covered workshop.

This site is current in operation and access cannot be arranged to carry out the required sampling works. Sampling works will hence be carried out at a later stage upon site availability.

 

3.3.9     YTML Lot No. 19-21 (Figure 6, Photo 22-28)

            This is no physical evidence on land contamination at this site (Photo 22-27), except for limited amount of engine oil leaking from the a parked trucks (Photo 28). A sampling point T19A was proposed to cover this stained area.  However, the site history suggested that there was a small area previously used as car repair works (1993 aerial photo). As the extent of car repair works carried out within this area could not be obtained, three sampling points (T19B - T19C) were proposed to cover this previous car repair area to ascertain whether the land was contaminated.

This site is fully vacated and is accessible for sampling.

 

3.3.10  YTML Lot No. 22A/22B (Figure 7, Photo 29-31)

The site history for these two sites are very similar : workshop or covered storage of dry goods. Although the site inspection has not revealed any evidence of land contamination, the vague site history (unclear what kind of workshop or storage) has rendered detailed sampling necessary to ascertain the land condition at this site. Due to the relative small scale of these sites, four sampling points (T22A-A , T22A-B, T22B-A & T22B-B), two at each site, were proposed.

This site is fully vacated and is accessible for sampling.

3.3.11  YTML Lot No. 22RP (Figure 7, Photo 32-36)

This site is currently being used as bricks manufacturing and material transfer. It was uncertain what type of work was carried out in the past but according to the current tenant, the site was a timber factory and had not been used as anything. However, no documentary proof could be found to substantiate this point. An oil stain on the ground was recovered at the site under a parked vehicle (Photo 36), but it was only considered to be an accidental spillage. Two number of samples (T22RP-A & T22RP-B) were proposed at the stained area and a representative location near the entrance of the site .

 

3.3.12  YTML Lot No. 23-24 (Photo 32-36)

            Although the site was classified under the Outline Development Plan as “Shipyard/sawmill/timber yard”, it could be observed from the aerial photographs that the site has been used as timber factory from 1973 to 1993. The site has since been a building materials (mainly sand and rubbles) transfer and sorting facility which are not land contaminating activities. As both site history and site inspection had revealed no suspicion on site contamination, no further site investigation works were proposed for this site.

 

3.3.13  YTML Lot No. 25 (Inaccessible, Photo 37)

This site was classified under the Outline Development Plan as “Shipyard/sawmill/timber yard”, and it could be observed from the aerial photographs that the site has been used as timber factory 1973 to 1993. The site has since been a timber yard which is not a land contaminating activity. Although site history suggests that this site is not contaminated, site inspection was not possible due to ownership reasons. A site inspection would need to be carried out to confirm the historical information and to propose further investigation requirement, if so required.

 

3.3.14  YTML Lot No. 26 (Inaccessible, Photo 38)

This site was classified under the Outline Development Plan as “Shipyard/sawmill/timber yard”, and it could be observed from the aerial photographs that the site has been used as timber factory from 1973 to 1993. The site has since been used as dry goods storage which presents no potential for land contamination. Although site history suggests that this site is not contaminated, site inspection was not possible due to ownership reasons. A site inspection would need to be carried out to confirm the historical information and to propose further investigation requirement, if so required.

 

3.3.15  YTML Lot No. 27 (Inaccessible, Photo 39-40)

This site was classified under the Outline Development Plan as “Shipyard/sawmill/timber yard”, and it could be observed from the aerial photographs that the site has been used as timber factory from 1973 to 1993. The site is currently used as timber factory which is not a land contaminating activity. Although site history suggests that this site is not contaminated, site inspection was not possible due to ownership reasons. A site inspection would need to be carried out to confirm the historical information and to propose further investigation requirement, if so required.

 

3.3.16  YTML Lot No. 28 (Figure 8, Photo 41-47)

This site was, at the time of the site survey, used as car repair workshop with services ranging from general servicing to vehicle body painting. As the whole site comprises similar services, four sampling points were proposed to representatively cover the site. Photo 46 reveals clearly a patch of oil stain on the ground. One of the four sampling locations (T28A) will be taken here to cover this hot spot for land contamination. The rest of the photos are general views of the motor repair workshop. Discoloration could be observed at various locations and the rest of the samples were taken to cover the vehicle body painting area as shown in Photo 47 (T28B), and car repair areas as shown in Photo 42 and 43 (T28C&D).

 

3.3.17  YTML Lot No. 29 (Photo 48-51)

This site was classified under the Outline Development Plan as “Shipyard/sawmill/timber yard”, and it could be observed from the aerial photographs that the site has been used as timber factory 1973 to 1993. The site has since been used as timber factory which is not a land contaminating activity. As both site history and site inspection had revealed no suspicion on site contamination, no further site investigation works were proposed for this site.

 

3.3.18  YTML Lot No. 30-31 (Photo 92-94 )

Site history showed that this site has been a sawmill from 1978-1982, and the site has been vacated since. For this site history, it can be concluded that no land contaminating activities had been carried out at this location. Hence no further site investigation works are proposed for this site. It was observed on site that there was no physical barrier separating this site and YTML Lot No. 32-33.

 

3.3.19  YTML Lot No. 32-33 (Figure 9, Photo 52-61)

Since 1977, the ship repair operations had ceased and the site was used as a sawmill. Site investigation has revealed no physical evidence on land contamination at the outdoor area but the current car repair works could have resulted in land contamination. In fact, oil stains could be observed at several two locations within the indoor car repair workshop and at one location outdoor. Five sampling points were proposed to cover the concerned car repair area and the filled jetty of this site. Sampling location T32A (Photo 60) and T32B (Photo 59) cover the indoor car repair areas where oil stains were observed, while T32C (Photo 61) covers the outdoor car repair station. T32D & E covers the filled jetty area.

 

3.3.20  YTML Lot No. 34 (Photo 62-63)

This site has only been used as a freight station and storage and hence not suspected to have been contaminated. Site inspection has confirmed that there is no signs of land contamination at this site and hence no further site investigation work were proposed for this site.

 

3.3.21  YTML Lot No. 35 (Figure 10, Photo 64-68)

This site was a machinery workshop but details of activities were not known. There was also no physical signs of land contamination from the visual inspection. As there is no clear information on what kind of machinery work was performed at this site, sampling was considered necessary. Three number of samples were proposed for this site. T35A (inside a subsurface service bay as shown in Photo 68) and T35C (Photo 67)were chosen to cover the two previous machine repair workshops while T35B was selected to cover the driveway of the site.

This site, together with YTML Lot No. 34 will be rented out to MTRC for use for a tenancy term of ~2 years. The lot is temporarily vacated (late Jan., 99) until MTRC take possession of the site.

 

3.3.22  YTML Lot No. 36-37 (Figure 11, Photo 69-77)

Machine repair works had been the main current operation at this site. Dissembled parts and equipment were found haphazardly scattered across the site. The top soil at the machinery workshop area was observed to be stained with oil (Photo 76). Sampling point T36D shall cover this hot spot. A large part of the site was covered with layers of metal sheets (Photo 77) and some of the top soil was on the metal sheets separated from the ground. The metal sheets were used to level the ground in order to stabilise the repair machinery. The metal sheets were placed some 15 years ago according to the current tenants. Some rusting was observed. There were strong physical evidences suggesting land contamination. Six sampling locations were selected to cover the two areas of most likely contamination : three number of samples (T36A,B&C) were proposed to cover the machinery workshop area and three others (T36D,E&F) to cover the dissembled parts storage area.

 

3.3.23  YTML Lot No. 38 (Figure 12, Photo 78)

            This site was observed to be piece of vacated land with a clean concrete surface. However, historical information has suggested that the site was previously used as a shipyard dated back to 1973. Due to the lack of further information, four sampling points (T38A - T38D) were proposed to cover the potentially contaminated area although there was no physical evidence on land contamination observed.

This site is fully vacated and is accessible for sampling.

 

3.3.24  YTML Lot No. 41-43 (Figure 13, Photo 79-86)

The structures at this site were being demolished at the time of the site investigation. There were no active ship repairing works observed but the historical information suggested that ship repair works were active up to 1993. Due to the lack of further information and that the whole site was extensively used as ship repair, eleven sampling points were selected to cover this large site. The sampling points were selected to cover the jetty area and the previously ship repair works area. There were no physical signs of land contamination, hence the sampling points were spread out to cover the whole site (T41A to K).

 

3.3.25  YTML Lot No. 44 (Figure 14, Photo 87-89)

Machinery repair works were observed during the site inspection. Although the tenancy to concrete manufacturer suggested that most past activities at this site were non-land contaminating, the current usage has rendered further site investigation necessary. Four numbers of samples were proposed for this site.

This site is current in operation and access cannot be arranged to carry out the required sampling works. Sampling works will hence be carried out at a later stage upon site availability.

 

3.3.26  YTML Lot No. 45-46 (Figure 15, Photo 90-91)

            This site was in use as concrete batching works at the time of the site survey and there was no observed sign of land contamination. However, prior to 1992, the site was operated as ship repair works. Four sampling point were proposed to cover the location where ship repair works was previously active as shown on the inspected aerial photographs.

This site is current in operation and access cannot be arranged to carry out the required sampling works. Sampling works will hence be carried out at a later stage upon site availability.

 

3.3.27  YTML Lot No. 73-74 (Photo 95-97)

A thirteen storey high industrial building sits on this site, with two levels of underground parking (Photo 97) which are the lowest levels of the building.  The building mainly comprises godown and offices, with limited industrial activities identified. No physical evidence of land contamination was observed at the lowest carpark level of the site. The aerial photograph records also show that the site has been used as storage and loading port for kaolin extracted from the nearby kaolin mines, since before 1966 until 1977, which is not a land contaminating operation. Together with the current land use, land contamination is not suspected for the site.

 

3.3.28  Salt Water Pumping Station (Figure 16, Photo 98 to 100)

A salt water pumping station was observed to be operating at this site. Sea water is pumped from Yau Tong Bay and further distributed to the Yau Tong area. Two storage tanks of unknown content is observed outside the  pumping station development.(Photo 99). These two tanks were above ground tanks supported by concrete “stands”. Neither leakage from the tanks nor stain on the ground area below and around the tanks could be observed. No contamination from these tanks could therefore be concluded. The plant room is located in the basement of the development and enclosed in solid concrete. No cracks of concrete was observed and no oil stain or land contaminating evidences could be observed. An “Insulating Oil Store” is observed at the site boundary. (Photo 100). This store was locked at the time of the survey and access could not be gained. The only concerned with this site is there might be land contaminants from this oil storage area which require further confirmation. Two sampling points were tentatively proposed for this location subject to further confirmation from site inspection. The sampling points shall cover the storage area and possible migration of contaminants, if any, to the adjacent site. The pumping station will be relocated to the sea boundary of the future reclaimed land. Aerial photograph records reveals that the site has been used as storage and loading port for kaolin extracted from the nearby kaolin mines prior to the construction of the existing pumping station, which is not a land contaminating operation.

 

3.3.29  Ice & Cold Storage Factory (Figure 17, Photo 101)

An ice factory utilising sea water pumped from Yau Tong Bay as the coolant  was observed to be operating at this site.  All manufacturing processes take place in the two storey tall plant, built on concrete foundation. The process was observed to be non-contaminating to the land and there was no physical sign of land contamination observed. As land contamination is not suspected at the site, no detailed assessment or sampling was proposed.

 

3.3.30  Gas Pigging Station (Figure 18, Photo 102)

Exposed pipe lines connecting to underground gas pipe network are installed at the site as a transfer station for town gas transmission.  No active operation or storage of chemicals could be observed on site.  The soil has no smell of petroleum or organics and no stains could be observed. The operation of the gas pigging station was not suspected to have contaminated the site. However, one storey covered storage or workshop of unknown operation can be observed from aerial photograph records. Due to the lack of conclusive information, although there was no physical evidence on land contamination observed, two sampling points were proposed to cover this storage area.

 

3.3.31  Maintenance Depot (Figure 19, Photo 103 to 106)

The site own by Civil Engineering Department (CED) was occupied by its contractor as maintenance depot / material storage. A two storey temporary site office built from used containers was observed in the centre of the site. Two storage tanks for petroleum products were observed, one at the center of the site, next to the site office (Photo 104) and another along the western site boundary (Photo 103). Oil stains were observed around each of these locations. Metallic construction parts were piled up beside the entrance of the site and in front of the site office (Photo 105 and 106).  Four sampling locations were proposed : one at the each petroleum storage tanks, one at the metal storage area and one outside the site office.

 

The site is still own by the government and used by her contractor, sampling shall be conducted at a later stage, when the consultant can gain access to the site and perform the excavation.

 

3.4            Summary of Site Information

For ease of reference, information regarding marine lot number and its respective figure number, photo number, amount of samples proposed and accessibility was tabulated under Table 3-4 below:

Table 3-4          Summary of Site Information

YTML number

Figure number

(Appendix IV)

Photo number

(Appendix IV)

No. of Samples

Accessibility for sampling

2-4

Inaccessible for inspection

5

1

1-4

3

ü

6-11

2

5-12

14

ü

12

3

13-16

3

ü

13-14

-

-

N/A

N/A

Govt. Lot

Ownership status pending

15

4

17-19

3

ü

54

5

20-21

6

x

19-21

6

22-28

3

ü

22A

7

29-31

2

ü

22B

7

29-31

2

ü

22RP

7

32-36

2

ü

23-24

-

32-36

N/A

N/A

25

Inaccessible for inspection

37

Inaccessible for inspection

26

Inaccessible for inspection

38

Inaccessible for inspection

Govt. Lot

Ownership status pending

27

Inaccessible for inspection

39-40

Inaccessible for inspection

28

8

41-47

4

ü

29

-

48-51

N/A

N/A

30-31

-

92-94

N/A

N/A

32-33

9

52-61

5

ü

34

-

62-63

N/A

N/A

35

10

64-68

3

ü

36-37

11

69-77

6

ü

38

12

78

4

ü

41-43

13

79-86

11

ü

44

14

87-89

4

x

45-46

15

90-91

4

x

73-74

-

95-97

N/A

N/A

Salt Water Pumping Station

16

98-100

2

x

Ice & Cold Storage Factory

17

101

N/A

N/A

Gas Pigging Station

18

102

2

x

Maintenance Depot

19

103-106

4

x

 

3.5            Inaccessible lots

The consultant could not gain assess to all of the marine lots during the site survey because some of the lots were owned by private land owners which had not participated in the development project.  As such, information pertaining to these lots were obtained from historical search only.  The inaccessible sites are as list in Table 3-5 below.

Table 3-5          Description of Inaccessible Sites

YTML No.

Current Operation

2-4

Ship yard

Govt. Lot between 13-14 and 15

Vacated

25

Storage

26

Vacated

Govt. Lot between 26 and 27

Vacated

27

Timber Factory

 

For the sites that are still in operation, in general, cessation of work will not happen until the commencement of the marine reclamation. Excavation works (sampling) within these sites will inevitably affect their normal operation to an unacceptable level. Hence, sampling works at these sites shall be carried out at a later date upon availability. Current operational status of the sites requiring detailed site investigation (soil sampling), as mentioned in Section 3.4, are as listed in Table 3-6 below:

Table 3-6          Current Operational Status of Sites that Require Soil Sampling

YTML No.

Current Operation

Available for Soil Sampling

5

Vacated

ü

6-11

Active operation as ship repair workshop

ü

12

Cement lorries repair

ü

15

Vacated

ü

54

Active operation as building material storage and distribution

x

19-21

Partially vacated

ü

22A

Parking

ü

22B

Parking

ü

22RP

Building materials transfer

ü

28

Active car repair workshop

ü

32-33

Vacated except structure at street side as car repair centre

ü

35

Will be rented to MTRC in the near future

ü

36-37

Active operation as machinery repair workshop and packed with equipment

ü

38

Vacated

ü

41-43

Rented to MTRC for conveyors, barge loading/mooring facility, temporary stockpiling and office purpose

ü

44

Machinery repair works

x

45-46

Active operation as concrete batching plant

x

Gas Pigging Station

Exposed gas pipe as transfer station for town gas transmission

x

Maintenance Depot

Occupied by CED contractor as material storage

x

Salt Water Pumping Station

Current salt water pumping for the Yau Tong Area

x

As indicated in the above table, six of the twenty sites that require detailed soil sampling exercise would not be available until the departure of current operators. Therefore, the forthcoming Detailed Contamination Assessment and Remediation Action Plan (RAP) shall only include sites which detailed soil sampling were carried out.  Detailed contamination assessment for the remaining site shall be conducted when the current occupants has moved out and the consultant can collect soil samples without constraints. Nevertheless, analysis results for sites of similar operational background can be used as references and most of these inaccessible sites are not expected to be extensively contaminated, if any. No construction work at any of these sites shall commence until the sites are confirmed to be free of contamination, or else, site remediation works must be completed. A supplementary CAP and RAP shall be submitted in due course for these sites.

Land clearance is scheduled to be completed by 1st June, 2001 according to the most updated master programme for the development.  A separate CAP for the remaining sites shall be prepared and submitted to EPD for approval upon availability of the inaccessible sites, or if they become consenting partners for the planned development.  Detailed contamination assessment and RAP for these remaining sites shall also be prepared for approval from the authorities accordingly.


4.               Discussion and recommendation for detailed site investigation   

4.1            Site Investigation Sampling Locations

            For the sites available for sampling alone, sixty-five (65) terrestrial soil sampling locations (Tn) (n=marine lot number) have been selected for the detailed site investigation work, the locations are as shown in Figure 4-1. Detailed locations are illustrated in figures contained in Appendix IV as indicated in the sub-headings for section 3.3 above.  Sampling locations were selected with reference to site survey results, i.e. at potential “hot spot” locations as described under Section 3.3 above. In accordance with the “Practice Note for Professional Persons on Contaminated Land Assessment and Remediation - Guidelines on Sampling and Analysis” (ProPECC PN 3/94) issued by the Environmental Protection Department, the selected sampling had covered sufficient samples using the grid sizes suggested in the said PROPECC Note.

 

            Marine mud sampling will not be included in the SI, due to technical problems foreseen in collecting such sample. The geotechnical consultant of the project team, Maunsell Geotechnical Services Ltd. (MGS) has advised us that due to the likely structure of the seawall, it is virtually impossible to carry out marine sampling exercise within 20m from the sea wall. In essence, the horizontal section of the seawall will result in a very shallow seabed and the vibrocore will simply bounce back from this horizontal section of the seawall without being able to collect samples of representative volume. Please refer to the letter from MGS contained in Appendix V for details. Also according to MGS, it will likely be some 20m away from the vertical seawall before a “marine mud” vibrocore sampling could be carried out. This will be the position where the horizontal seawall ends. According to the distribution of project work, marine mud contamination assessment is being carried out by Maunsell Environmental Management Consultants Ltd. (MEMCL). We understand that the assessment carried out MEMCL is in a different context, but the influence radius of contaminants spreading from the land to the marine area should not be extensive as to have affected the marine mud at more than 20m away. As such, the existing vertical seawall will be treated as the physical divider of responsibility, and this CAP shall concentrate on contamination assessment at the “land” area. For jetty areas which protrude into the marine area, a “land” sample as close to the sea as possible will be collected to ascertain the likelihood of contaminants migration into the marine area.


 Figure 4-1      Locations of Soil and Groundwater Sampling Points (detail sampling points are shown in Appendix IV)


5.              methodology of detailed site investigation

5.1                        Terrestrial Soil Sampling Specification

(i)       Soil samples shall be taken at nominal depths of 0.5m, 1.5m, and 3m below the hard standing cover at the boreholes to detect any signs of land contamination. The sample depths and locations may vary slightly subject to geological condition or any obvious contamination at different strata.

(ii)      For each borehole, a starting pit is to be opened in two steps. i.e. at 0.5m and 1.5m below the hard standing cover for bulk sampling of soil for subsequent contamination analysis. Soil samples shall be shovelled into 1-L glass bottles. If the bed rock is encountered before the next sampling depth, sampling should cease immediately.

(iii)    At 2.8m below the hard standing cover, a soil sample shall be taken by a U70 sampler for contamination analysis to represent the third sample at 3m depth.

(iv)    For the boreholes / trial pits encountering groundwater tables, groundwater samples shall be taken when the groundwater tables are first encountered. The holes shall be allowed to stabilise for 24 hours before the second samples are taken. i.e. two groundwater samples are required, one before and one after stabilisation of the boreholes.

(v)     Soil and groundwater samples taken from the boreholes shall be sent to the laboratory for analysis.

5.2            Laboratory analysis

Collected soil and water samples shall be sent to a HOKLAS accredited laboratory for analysis. Parameters to be tested and their limit of report shall be as listed in the following table:

Parameters for analysis

Limit of Report

 

Soil Samples (mg/kg/dry wt)

Water Samples (mg/L)

TBT (Tributyl Tin)

0.5mg Sn/kg

5ng Sn/L

TPH (Total Petroleum Hydrocarbon)

 

 

C6 - C9 Fraction

2

20

C10 - C14 Fraction

50

25

C15 - C28 Fraction

100

25

C29 - C36 Fraction

100

25

BETX (Benzene, Toluene, Ethylbenzene and Xylene)

 

 

Benzene

0.2

2

Toluene

0.2

2

Chlorobenzene

0.2

2

Ethylbenzene

0.2

2

meta- & para-Xylene

0.4

4

ortho-Xylene

0.2

2

Total Polychlorinated Biphenyls

0.1

1

Various Polyaromatic Hydrocarbons

0.5-1

2-4

Copper

0.05

1

Lead

0.05

1

Chromium

0.05

1

Mercury

0.02

0.5

Nickle

0.05

1

Moisture Content

0.1%

-

PESD (Particle Sizing Distribution)

for sieve sizes: 2mm, 710mm, 300mm, 150mm, 106mm, 75mm, 65mm and -63mm

for sieve sizes: 2mm, 710mm, 300mm, 150mm, 106mm, 75mm, 65mm and -63mm

Potential land contaminating activities identified at the sites mainly involves ship repair and machinery repair works. These  activities consume and generate large amount of oil and petroleum by-products, which shall be the major land contaminants for the sites. Soil and ground water criteria used in The Netheralnds for contaminated land (the Dutch List) is a generally accepted standard for assessing land contamination in Hong Kong. Appropriate components from the Dutch List, i.e., those present in the oil products, petroleum product and paints that are commonly used by the repair industry, were selected for analysis. Some listed compounds were not used at the sites, e.g. pesticides and part of the chlorinated hydrocarbon group and hence these compounds will not be tested. These parameters shall be used solely to determine whether the land has been contaminated or not.

 

Should soil dumping to landfill sites be recommended as a remedial action, a further set of TCLP tests would need to be carried out to determine the suitability of landfilling. If necessary, pre-treatment or stabilisation would be necessary prior to landfilling.

 

5.3            Precautions Against Pollution

In the execution of the Works, the Contractor shall take all necessary measures to secure the protection of all seas, drains and the like against silting, pollution, contamination of water supplies and injury to fish or plant life, and shall comply with all statutory requirements for environmental protection.

Special attention shall be paid to the underground tanks that might exist, although there is currently no evidence to suggest their existence. Manual excavation is especially recommended to prevent rupture to these underground tanks. Any underground tanks located shall be removed prior to further soil sampling.

 

5.4            Clean up

All solid and liquid wastes and hazardous substances introduced by the Contractor (e.g. solvents, cleaners, waste oils, etc.) shall be handled and/or disposed of in full compliance with all applicable regulations, ordinances and rules.

As soon as the Works are completed, the Contractor shall clear the premises of debris, waste materials and equipment remaining.

 

5.5            Reinstatement

On completion of Works, the Contractor shall fill in and compact all pits and boreholes using uncontaminated materials as approved by the Consultant, level and reinstate the site. All debris and surplus materials shall be removed from the site.

 

5.6            Reporting

The report shall contain the following information:

1.    Borehole and sample number

2.    Date and time of sampling

3.    Type of hole (starting pits/ drilled holes etc.)

4.    Sampling method (bulk sample, U70)

5.    Type of sample (soil or groundwater)

6.    Brief description of the sample, including colour, smell or any special observations.

7.    Parameters for analysis for each sample

8.    Results of analysis

9.    Any other findings


6.          Technical Specifications

6.1            Soil and Groundwater Sampling and Analysis

6.1.1     Soil Sampling Methodology

Bulk samples of soil shall be taken at 0.5m and 1.5m by opening pits in two steps. Soil samples shall be shovelled indiscriminately into 1-litre glass bottles to the neck level. Shovels shall be thoroughly cleaned after taking each sample to ensure that there is no cross-strata contamination.

Sample containers shall be tightly sealed as soon as the samples are taken. Headspace shall be minimised, and the samples refrigerated to 4°C as soon as possible. Refrigeration shall be maintained until analysis, and the samples to be analysed as soon as possible.

The third sample at 3m depth shall be taken by a U70 sampler - a rigid metal tube of 70mm internal diameter and 450mm length by driving into the soil by force from 2.8m depth.

 

6.1.2     Groundwater Sampling Methodology

Groundwater samples shall be taken from all of the boreholes when the groundwater table is first encountered. Due to the uncertainty in the time needed to achieve a new diffusion equilibrium inside the borehole, duplicate samples shall be taken. i.e. one before and one after stabilisation for at least 24 hours. The first batch of groundwater shall be pumped out after the first sample to allow a new equilibrium to reach.

In taking the samples, a bailer shall be lowered to the hole until the water table is encountered. Water samples should be taken from each hole twice and combined to provide a composite sample into 1-litre glass bottle to the neck level. The samples shall be preserved at 4°C, labelled and delivered to the Laboratory on the same day.

 

6.1.3     Labelling, Transportation and Storage of Samples

Samples shall be well-contained, sealed, labelled and preserved at about 4°C especially for those containing relatively volatile contaminants. Samples shall be taken to Laboratory for analysis within the same day.

Immediately after being taken, each sample shall be labelled.  The label shall be clearly legible and durable. The label shall show the following information :

 

 

1.      Name of client and contractor

2.      Date

3.      Location of sample (borehole no. etc.)

4.      Depth from which the sample was taken

5.      Type of samples

6.      Brief description of the soil, colour, smell or any special observation

7.      The signature or mark of the supervisor

8.      Type of chemical analysis to be performed on the sample e.g. TRPH, BTEX, Lead etc.

 

6.1.4     Flushing Medium

Flushing medium for drilling should be avoided as far as possible. In case of genuine need, oil-free water shall be used subject to the Consultant’s agreement.

 

6.1.5     Safety measures

          Site staff and the sampling team shall be instructed on the safety precautions. They should wear proper protective boots and gloves and observe good practice of hygiene. Direct or indirect contact with potentially contaminated materials should be avoided. The possibility of fire/explosion must be minimised and all workers on-site should be familiar with emergency procedures in case of accidents.


7.              Further works

Upon endorsement of the CAP by the EPD, the actual site investigation for land contamination impact assessment shall be conducted accordingly.  Soil and groundwater samples shall be collected and tested as described in this CAP to provide site specific information for the assessment. A Remedial Action Plan (RAP) shall be prepared to formulate necessary remedial measures if land contamination is confirmed.

 

Land contamination assessment for some sites were deemed impossible at this stage. These sites are either inaccessible for sample collection or unable to collect samples due to obstruction from current operations. Furthermore, some of the owners of these inaccessible sites are, to date, non-consenting to the planned development. The developer for this project shall take up the responsibility of remediation for these sites should these sites become consenting partners for the development. Otherwise, these sites shall be excluded from the scope of land contamination assessment and the owner of these sites shall be responsible for their own sites’ remediation, if so required, should they decide to re-develop their sites. In such cases, a supplementary study on possible contamination migration from the remaining sites shall be conducted depending on likely contamination status of the particular adjacent site.

 

As mentioned under section 3.5 above, land clearance is scheduled to be completed by 1st June, 2001 according to the most updated master programme for the development.  A separate CAP for the remaining sites shall be prepared and submitted to EPD for approval upon availability of the inaccessible sites, or if they become consenting partners for the planned development.  Detailed contamination assessment and RAP for these remaining sites shall also be prepared for approval from the authorities accordingly if land contamination is confirmed.

 

For the remaining sites, reference will be made to analysis results obtained from other sites of similar operation history and nature. However, detailed site investigation at these sites would be necessary upon availability of access.


APPENDIX I

 

Industrial Activities and Possible Contaminants Identified during the Preliminary Land Contamination Assessment


Industrial Activities and Possible Contaminants Identified during the On-Site Survey

Reference No. in Figure1-1

Company Name

Description

Possible Contaminants

1

Bonanza Saw-Mill Ltd.

Saw-mill, wood storage

Less significant

2

Universal Dockyard Ltd.

Shipyard

Petroleum hydrocarbon, heavy metals

3

Yau Wing Co. Ltd.

Ship repair workshop, in-house DG store

Petroleum hydrocarbon, heavy metals

4

Redland Cement Ltd.

Cement manufacturing

Less significant

5

Hong Kong Dredging Ltd.

Office, workshop

Petroleum hydrocarbon, heavy metals

6

Man Wah Ltd.

Bricks and cement packaging

Less significant

7

Kwok Wing Ltd.

Vacant

Insufficient information

8

Hop Fat Metals

Tin Wai Warehouse

Vacant

Insufficient information

9

Wing Tai Cheong Saw-Mill

Saw-mill, wood storage

Less significant

10

EI Freight (HK) Ltd.

Cargo storage

Less significant

11

Bonanza Saw-Mill Ltd.

Saw-mill, wood storage

Less significant

12-1

Kei Yip Car Repair

Car repair workshop

Petroleum hydrocarbon, heavy metals

12-2

Kwok Luen

Tyre supplier

Less significant

13

Sing Tai Saw-Mill

Saw-mill, wood storage

Less significant

14

N.A.

Vacant

Insufficient information

15

Rainbow Transportation and Warehouse Ltd.

Warehouse, no DG storage

Less significant

16

Wai Sing Car Repair

Car repair workshop

Petroleum hydrocarbon, heavy metals

17

Wing Wui Co. Ltd.

Cement and bricks manufacturing (ship repair in the past)

Petroleum hydrocarbon, heavy metals

18

Brigantine Services Ltd.

Machine repair workshop

Petroleum hydrocarbon, heavy metals

19

Sam Woo Ship Building Ltd.

Sam Woo Engineering Equipment Ltd.

Machine workshop

Petroleum hydrocarbon, heavy metals

20

N.A.

Vacant, abandoned land, signs of uncontrolled waste dumping

Insufficient information

21

Goltens Hong Kong Ltd.

Ship repair workshop

Petroleum hydrocarbon, heavy metals

22

Kwong Hing Cement

Cement manufacturing

Less significant

23

Agincourt Industrial Building

Multi-storey industrial building

Insufficient information

 Location of Activities Identified at the Subject Site During Preliminary Assessment


 

APPENDIX II

 

Requests & Responses from

Various Parties on Site Historical Survey


APPENDIX III

 

OUTLINE DEVELOPMENT PLAN (1991)


APPENDIX IV

Photographs and Layout Plan for Sites Suspected to Suffer from Land Contamination
Photographs and Layout Plan for TYML Lot No. 5
Photographs and Layout Plan for TYML Lot No. 6-11
Photographs and Layout Plan for TYML Lot No. 12
Photographs and Layout Plan for TYML Lot No. 15
Photographs and Layout Plan for TYML Lot No. 54
Photographs and Layout Plan for TYML Lot No. 19-21
Photographs and Layout Plan for TYML Lot No. 22A, 22B and 22RP
Photographs for TYML Lot No. 23-24
Photographs for TYML Lot No. 25
Photographs for TYML Lot No. 26
Photographs for TYML Lot No. 27
Photographs and Layout Plan for TYML Lot No. 28
Photographs for TYML Lot No. 29
Photographs for TYML Lot No. 30-31
Photographs and Layout Plan for TYML Lot No. 32-33
Photographs for TYML Lot No. 34
Photographs and Layout Plan for TYML Lot No. 35
Photographs and Layout Plan for TYML Lot No. 36-37
Photographs and Layout Plan for TYML Lot No. 38
Photographs and Layout Plan for TYML Lot No. 41-43
Photographs and Layout Plan for TYML Lot No. 44
Photographs and Layout Plan for TYML Lot No.45-46
Photographs for TYML Lot No.73-74
Photographs and Layout Plan for Salt Water Pumping Station
Photographs and Layout Plan for Ice & Cold Storage Factory
Photographs and Layout Plan for Gas Pigging Station
Photographs and Layout Plan for Maintenance Depot

APPENDIX V

 

Letter from Project Geotechnical Consultant Explaining Problems Encountered with Marine Mud Sampling