6 WASTE management

6.1 Introduction

6.1.1 This section identifies the types of wastes that are likely to be generated during the construction phase and evaluates the potential environmental impacts that may result from these waste arisings. The main solid waste issues are related to dredged marine sediment and other construction waste arisings, and the potential biogas risk due to the release of methane gas from the sediment underneath the reclaimed area during construction or after development. Mitigation measures and good site practice, including waste handling, storage and disposal, will be recommended with reference to the applicable waste legislation and guidelines. An assessment of the potential biogas emission from the undredged area at the proposed reclamation is presented in Section 11.

6.2 Environmental Legislation, Policies, Plans, Standards and Criteria

6.2.1 The criteria and guidelines for assessing waste management implications are outlined in Annex 7 and Annex 15 of the Technical Memorandum on Environmental Impact Assessment Ordinance (EIAO-TM), respectively.

6.2.2 The following legislation relates to the handling, treatment and disposal of wastes in the Hong Kong SAR and will be used in assessing potential impacts:

· Waste Disposal Ordinance (Cap. 354);

· Waste Disposal (Chemical Waste) (General) Regulation (Cap. 354);

· Land (Miscellaneous Provisions) Ordinance (Cap. 28);

· Public Health and Municipal Services Ordinance (Cap. 132) - Public Cleansing and Prevention of Nuisances (Urban Council) and (Regional Council) By-laws; and

· Dumping At Sea Ordinance (Cap. 466).

6.2.3 The following documents, circulars and guidelines which relate to waste management and disposal in the Hong Kong SAR will also be referred to during this study:

· Waste Disposal Plan for Hong Kong (December 1989), Planning, Environment and Lands Branch, Hong Kong Government Secretariat;

· Environmental Guidelines for Planning in Hong Kong (1990), Hong Kong Planning Standards and Guidelines, Hong Kong Government;

· New Disposal Arrangements for Construction Waste (1992), Environmental Protection Department and Civil Engineering Department;

· Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes (1992), Environmental Protection Department;

· Waste Reduction Framework Plan, 1998-2007 (1998), Planning, Environment and Lands Branch, Hong Kong Government Secretariat;

· Works Bureau Technical Circular (WBTC) No. 2/93, Public Dumps;

· WBTC No. 2/93B, Public Filling Facilities;

· WBTC No. 16/96, Wet Soil in Public Dumps;

· WBTC No. 4/98, Use of Public Fill in Reclamation and Earth Filling Projects;

· WBTC No. 4/98A, Use of Public Fill in Reclamation and Earth Filling Projects;

· WBTC No. 5/98, On Site Sorting of Construction Waste on Demolition Sites;

· WBTC No. 5/99, Trip-ticket System for Disposal of Construction and Demolition Material;

· WBTC No. 5/99A, Trip-ticket System for Disposal of Construction and Demolition Material;

· WBTC No. 3/2000, Management of Dredged / Excavated Sediment;

· WBTC No. 25/99, Incorporation of Information on Construction and Demolition Material Management in Public Works Subcommittee Papers;

· WBTC No. 25/99A, Incorporation of Information on Construction and Demolition Material Management in Public Works Subcommittee Papers (Amendment 1);

· WBTC No. 25/99B Incorporation of Information on Construction and Demolition Material Management in Public Works Subcommittee Papers;

· WBTC No. 12/2000, Fill Management; and

· WBTC No. 29/2000, Waste Management Plan.

Waste Management

6.2.4 The Waste Disposal Ordinance (WDO) prohibits the unauthorised disposal of wastes. Construction waste is not directly defined in the WDO but is considered to fall within the category of “trade waste”. Trade waste is defined as waste from any trade, manufacturer or business, or any waste building, or civil engineering materials, but does not include animal waste. Under the WDO, wastes can be disposed of at sites licensed by the EPD.

6.2.5 The Public Cleansing and Prevention of Nuisance By-Laws provides control on illegal tipping of wastes on unauthorised (unlicensed) sites.

Marine Sediment

6.2.6 The WBTC No. 3/2000 sets out the new management framework for dredged / excavated sediment. This Technical Circular outlines the new procedures to be followed in assessing and classifying the sediment and explains the marine disposal arrangement for the classified material. All projects which involve the marine disposal of dredged / excavated sediment, except those projects or portions of projects whose construction work will commence before 31 December 2001, shall follow the new management framework. Under the preliminary construction programme for WDII, the dredging works are scheduled to commence in 2004 and, therefore, the requirements of WBTC No. 3/2000 should be followed. The new sediment quality criteria for the classification of sediment are presented in Table 6.1.

6.2.7 Dumping permits from EPD are required for marine disposal of dredged materials.

Chemical Waste

6.2.8 Under the Waste Disposal (Chemical Waste) (General) Regulations, all producers of chemical waste must register with EPD and treat their wastes, either utilising on-site plant licensed by EPD, or arranging for a licensed collector to transport the wastes to a licensed facility. The regulation also prescribes the storage facilities to be provided on site, including labelling and warning signs, and requires the preparation of written procedures and training to deal with emergencies such as spillages, leakages or accidents arising from the storage of chemical wastes.

Construction and Demolition (C&D) Materials

6.2.9 The current policy related to the dumping of C&D material^([1]) is documented in the Works Branch Technical Circular No. 2/93, ‘Public Dump’. Construction and demolition materials that are wholly inert, namely public fill, should not be disposed of to landfill, but taken to public filling areas which usually form part of reclamation schemes. The Land (Miscellaneous Provisions) Ordinance requires that dumping licences are obtained by individuals or companies who deliver public fill to public filling areas. The licences are issued by the Civil Engineering Department (CED) under delegated powers from the Director of Lands.

6.2.10 In addition to the Works Branch Technical Circular / WBTC, EPD and CED have produced a leaflet titled ‘New Disposal Arrangements for Construction Waste’ (1992) which states that C&D material with less than 30% by weight of inert material (that is, public fill) will be accepted at landfill. If the material contains more than 30% inert material, the waste must be sorted with suitable material and sent to public filling area and the non-inert material (that is, C&D waste) sent to landfill for final disposal.

6.3 Assessment Methodology

General

6.3.1 The criteria for assessing waste management implications are outlined in Annex 7 of the EIAO-TM. The methods for assessing potential waste management impacts during construction follow those presented in Annex 15 of the EIAO-TM and include the following:

· estimation of the types and quantities of the wastes generated;

· assessment of potential impacts from the management of solid waste with respect to potential hazards, air and odour emissions, noise, wastewater discharges and transport; and

· impacts on the capacity of waste collection, transfer and disposal facilities.

Marine Dredged Materials

6.3.2 The Phase I marine site investigation works of WDII were carried out in February 2000 and included laboratory testing of contaminants to determine the level of contamination in the marine sediments at the reclamation location. The works included vibrocoring at six locations (MV1, MV4, MV5, MV6, MV7 and MV8) around the HKCEC and near the Wan Chai waterfront to obtain sediment samples for chemical testing (Figure 6.1). The Phase II marine site investigation works commenced in late September 2000 and included sampling locations near the Wanchai Public Cargo Working Area (PCWA) (MV20), the Royal Hong Kong Yacht Club (MV9 and MV15) and at the Causeway Bay Typhoon Shelter (MV10, MV11, MV12, MV13, MV14, MV16, MV17, MV18 and MV19).

6.3.3 Each sub-sample recovered from the Phases I and II vibrocoring was tested in the laboratory for the following parameters unless otherwise specified:

(i) Metals concentrations including chromium (Cr), copper (Cu), mercury (Hg), lead (Pb), cadmium (Cd), nickel (Ni), zinc (Zn), silver (Ag) and arsenic (As).

(ii) Concentrations of organic compounds including total polychlorinated biphenyls (PCBs), polyaromatic hydrocarbons (PAHs), and tributyltin (TBT) for each sub-sample from the top three sampling depths of each vibrocoring location.

(iii) Redox potential.

(iv) Total organic carbon (TOC) (Phase I samples only).

(v) Sediment oxygen demand (SOD) (Phase I samples and those Phase II samples acquired from the Causeway Bay Typhoon Shelter).

6.3.4 Elutriate tests were also conducted to assess the likelihood of release of contaminants from sediment to the water, when the seabed is disturbed during dredging. If the contaminant levels are higher in the elutriates in comparison with the sample of marine water from the same site, it can be concluded that the contaminants are likely to be released into the open waters during dredging activities. The potential water quality impacts associated with the dredging of sediment are discussed in Section 5 of this Report.

6.3.5 Under the new management and classification system, dredged sediments destined for marine disposal are classified according to their level of contamination by 13 contaminants (Table 6.1).

Table 6.1 Sediment Quality Criteria for the Classification of Sediment

Contaminants	LCEL	UCEL
Heavy Metal (mg/kg dry weight)
Cadmium (Cd)	1.5	4
Chromium (Cr)	80	160
Copper (Cu)	65	110
Mercury (Hg)	0.5	1
Nickel (Ni)	40	40
Lead (Pb)	75	110
Silver (Ag)	1	2
Zinc (Zn)	200	270
Metalloid (mg/kg dry weight)
Arsenic	12	42
Organic-PAHs (µg/kg dry weight)
PAHs (Low Molecular Weight)	550	3160
PAHs (High Molecular Weight)	1700	9600
Organic-non-PAHs (µg/kg dry weight)
Total PCBs	23	180
Organometallics (µg-TBT L^-1 in interstitial water)
Tributyltin	0.15	0.15

Source: Appendix A of WBTC No. 3/2000 Management of Dredged / Excavated Sediment

Note: LCEL – Lower Chemical Exceedance Level

UCEL – Upper Chemical Exceedance Level

6.3.6 Sediments are categorised with reference to the LCEL and UCEL, as follows:

Category L Sediment with all contaminant levels not exceeding the LCEL. The material must be dredged, transported and disposed of in a manner that minimises the loss of contaminants either into solution or by suspension.

Category M Sediment with any one or more contaminant levels exceeding the LCEL and none exceeding the UCEL. The material must be dredged and transported with care, and must be effectively isolated from the environment upon final disposal unless appropriate biological tests demonstrate that the material will not adversely affect the marine environment.

Category H Sediment with any one or more contaminant levels exceeding the UCEL. The material must be dredged and transported with great care, and must be effectively isolated from the environment upon final disposal.

6.3.7 In the case of Category M and Category H contamination under the new system, the final determination of appropriate disposal options, routing and the allocation of a permit to dispose of material at a designated site will be made by EPD and the Marine Fill Committee (MFC) in accordance with the WBTC No. 3/2000.

6.4 Baseline Conditions

Existing Sediment Characteristics

6.4.1 The results of the marine sediment quality analysis from Phase I and Phase II marine site investigation works, as compared with the new sediment quality criteria for the classification of sediment, are presented in Tables 6.2 and 6.3, respectively.

6.4.2 The sediment testing results indicate that Category H sediment was found at all but two of the 18 vibrocore locations due to high contaminant levels of Ag, Cu, Pb, Zn and Hg that exceed the UCEL of these five metals. At vibrocores MV11, MV12, MV17, MV18 and MV19, all located within the Causeway Bay Typhoon Shelter, the reported contaminant level of Total PCBs exceeds the LCEL by 10 times (in approximately the first 1 m below the seabed, except at MV11 with a depth of approximately 2 m). It is therefore likely that Tier III biological screening would be required for future sediment sampling in the typhoon shelter to be carried out in the further ground investigation works at the design phase of the Project. At vibrocore MV17, the reported contaminant level of high molecular weight PAHs is in exceedance of the UCEL. It should be noted that MV17 and MV18 are located within the areas of the Causeway Bay Typhoon Shelter where mud is proposed to be left in place. The other areas of the typhoon shelter would be fully dredged.

6.4.3 At vibrocores MV5, MV13 and MV18 where the marine mud extends to a greater depth, there was a decrease in the level of metal contamination from surface to deeper sediments. At vibrocore MV14, however, Category H contamination was found at sampling depth –7.0 to –7.9 mPD. Sediment at vibrocores MV16 (located outside Causeway Bay Typhoon Shelter) and MV20 (located within the PCWA) is classified as Category L.

6.4.4 The measurements of redox potential indicate strongly anaerobic conditions within the sediments, particularly to depths of up to 3 or 4 metres. The results of EPD’s routine monitoring of marine sediment quality also indicate that the sediment is largely anaerobic (also refer to Section 9.3.2 of this Report). Only at vibrocore MV20 was a positive redox potential measured in the upper layer of sediment.

Table 6.2 Results of Sediment Quality Analysis from the Phase I Marine Site Investigation Works

Vibrocore	Sampling Depth (m)	Metals and Metalloid Content (mg kg^-1)									(mg kg^-1)				(mg-TBT L^-1)	Overall Classification
		Ag	As	Cd	Cr	Cu	Ni	Pb	Zn	Hg	Total PCBs	PAHs Low^(1)	PAHs High^(2)	TBT in Sediment	TBT in Interstitial water
MV1	0.55 - 0.9 m	5.7	9	0.9	67	297	32	66	314	0.62	14	<50	370	81	0.3	Category H
	1.0 - 1.9 m	3.6	9	0.7	47	205	24	85	222	0.62	20	<50	300	68	<0.3	Category H
	2.0 - 2.9 m	2.5	8	0.5	64	214	24	96	254	1	120	810	7400	16	<0.3	Category H
	3.0 - 3.9 m	<0.5	3	<0.5	7	2	6	9	16	<0.05						Category L^(5)
MV4	0.25 - 0.9 m	4.6	7	0.9	57	284	27	72	359	0.66	59	97	620	55	<0.3	Category H
	1.0 - 1.9 m	3.8	8	0.5	44	180	24	58	204	0.35	32	93	720	39	<0.3	Category H
	2.0 - 2.9 m	3.7	9	0.8	62	269	27	112	364	0.96	100	79	680	17	<0.3	Category H
	3.0 - 3.9 m	3.6	8	0.7	62	133	26	115	369	1.59						Category H
MV5	0.3 - 1.0 m	5.6	8	1	71	331	30	71	331	1.05	21	250	820	96	<0.3	Category H
	1.0 - 1.9 m	4.6	7	0.7	61	374	30	62	258	0.45	18	<50	310	76	<0.3	Category H
	2.0 - 2.9 m	3.6	7	0.7	61	249	30	69	228	0.67	63	130	300	17	<0.3	Category H
	3.0 - 3.9 m	1	5	<0.5	23	29	12	48	138	0.47						Category L^(5)
	6.5 - 7.0 m	<0.5	4	<0.5	7	5	5	19	22	<0.05						Category L^(5)
	7.0 - 7.9 m	<0.5	<1	<0.5	2	2	1	11	6	<0.05						Category L^(5)
	8.0 - 8.9 m	<0.5	<1	<0.5	1	<1	<1	6	<5	<0.05						Category L^(5)
	9.0 - 9.9 m	<0.5	<1	<0.5	<1	1	1	3	<5	<0.05						Category L^(5)
	10.0 - 10.9m	<0.5	<1	<0.5	<1	<1	<1	3	<5	<0.05						Category L^(5)
	11.0 - 11.6m	<0.5	2	<0.5	<1	<1	<1	4	<5	<0.05						Category L^(5)
MV6	1.0 - 1.9 m	4.4	8	0.9	67	381	30	78	337	0.64	21	140	1000	74	<0.3	Category H
	2.0 - 2.9 m	4.8	8	0.9	74	323	29	125	394	2.11	110	690	2800	40	<0.3	Category H
	3.0 - 3.9 m	<0.5	4	<0.5	10	12	9	59	67	1.06	30	220	1300	3	<0.3	Category H
MV7	0.1 - 0.8 m	3.9	10	0.6	45	241	25	53	175	0.33	5	<50	200	34	<0.3	Category H
MV8	0.5 - 0.9 m	7.5	9	1.1	64	242	28	68	295	0.49	15	53	390	102	<0.3	Category H
	1.0 - 1.9 m	2.7	8	0.5	48	130	19	122	281	1.12	120	1100	7200	13	<0.3	Category H
	2.0-2.9m	<0.5	3	<0.5	12	4	10	14	28	<0.05	<2	<50	<150	1	<0.3	^(6)
	3.0-3.9m	<0.5	4	<0.5	10	4	9	14	25	<0.05						Category L^(5)

Notes:

1. Low molecular weight PAHs, that is, acenaphthene, acenaphthylene, anthracene, fluorene, naphthalene and phenanthrene.

2. High molecular weight PAHs, that is, benzo[a]anthracene, benzo[a]pyrene, chrysene, dibenzo[a,h]anthracene, fluoranthene, pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, indeno[1,2,3-c,d]pyrene and benzo[g,h,i]perylene.

3. Values in underline indicate Category M sediment under WBTC No. 3/2000.

4. Values in bold indicate Category H sediment under WBTC No. 3/2000.

5. Provisional classification based on available testing results for analysis of metals and metalloid content.

6. Classification cannot be determined due to detection limit of TBT in interstitial water being higher than UCEL (as insufficient sample size recovered from vibrocores, the testing laboratory experienced difficulties in extracting sufficient interstitial water to achieve the required detection limit).

Table 6.3 Results of Sediment Quality Analysis from the Phase II Marine Site Investigation Works

Vibrocore	Sampling Depth (m)	Metals and Metalloid Content (mg kg^-1)									(mg kg^-1)				(mg-TBT L^-1)	Overall Classification
		Cu	Cd	Cr	Pb	Ni	Zn	Hg	Ag	As	Total PCBs	PAHs Low^(1)	PAHs High^(2)	TBT in Sediment	TBT in Interstitial water
MV9	0-0.9M	169	0.6	48	59	20	202	0.5	5	4	58	430	730	23	<0.015	Category H
	1.0-1.9M	4	<0.5	8	14	5	19	0.05	<0.5	2	2	<50	<100	<0.5		Category L
	2.0-2.9M	2	<0.5	8	10	5	15	<0.05	<0.5	3	<2	<50	<100	<0.5		Category L
	3.0-3.9M	3	<0.5	16	14	7	19	<0.05	<0.5	4	<2	<50	<100	<0.5		Category L
	4.0-4.6M	3	<0.5	10	35	9	24	0.12	<0.5	3						Category L
MV10	0-0.84M	208	0.8	70	103	17	264	1.39	2.7	12	120	100	1100	2390	0.022	Category H
MV11	0-0.9M	346	1.3	103	158	36	415	1.36	4.5	9	460	220	1600	216	<0.015	Category H
	1.0-1.9M	137	0.8	65	321	27	652	1.6	1.9	9	430	680	5700	10		Category H
	2.0-2.9M	23	<0.5	42	52	29	108	0.38	<0.5	6	10	<50	190	3		Category L
	3.0-3.9M	5	<0.5	9	13	6	20	0.05	<0.5	3	<2	<50	130	1		Category L
	4.0-4.9M	2	<0.5	9	10	5	13	<0.05	<0.5	4						Category L
	5.0-5.7M	11	<0.5	35	21	15	48	<0.05	<0.5	7						Category L
MV12	0-0.9M	322	1.8	90	175	35	518	2.87	4.3	10	4200	240	3600	61	<0.015	Category H
	1-1.9M	140	0.7	48	260	23	400	1.46	1.8	9	200	330	3600	<0.5		Category H
	2-2.9M	21	<0.5	49	51	31	108	0.26	<0.5	5	8	<50	130	<0.5		Category L
	3-3.9M	10	<0.5	12	18	9	34	0.11	<0.5	2	4	<50	<100	<0.5		Category L
	4-4.9M	16	<0.5	38	33	26	79	<0.05	<0.5	2						Category L
	5-5.9M	10	<0.5	21	20	7	29	<0.05	<0.5	6						Category L
MV13	0-0.9M	407	1.2	94	86	37	357	1.36	7.2	10	50	99	610	77	<0.015	Category H
	1.0-1.9M	157	0.6	65	97	32	227	0.64	2	8	65	<50	450	202		Category H
	2.0-2.9M	59	<0.5	36	51	25	111	0.39	<0.5	4	<2	<50	410	2		Category L
	3.0-3.9M	2	0.9	10	52	4	32	<0.05	<0.5	1	<2	<50	<100	<0.5		Category L
	4.0-4.9M	2	1.1	5	75	4	38	<0.05	<0.5	2						Category L
	5.0-5.9M	2	0.8	6	111	4	22	0.11	<0.5	1						Category L
	6.0-6.9M	1	<0.5	6	9	2	<5	0.05	<0.5	<1						Category L
	7.0-7.9M	2	<0.5	6	11	2	6	0.05	<0.5	<1						Category L
	8.0-8.9M	<1	<0.5	2	5	1	<5	<0.05	<0.5	<1						Category L
MV14	0-0.9M	358	1.1	79	87	31	333	0.72	6.9	10	57	120	830	126		Category H
	1.0-1.9M	191	0.7	58	100	26	262	0.82	2.1	9	180	210	1200	57		Category H
	2.0-2.9M	193	0.7	67	120	22	289	0.84	2.4	8	92	320	110	98		Category H
	3.0-3.9M	63	<0.5	35	118	18	199	0.58	0.9	8	95	62	560	13		Category H
	4.0-4.9M	59	<0.5	37	110	18	234	0.88	0.8	8						Category H
	5.0-5.9M	35	<0.5	21	67	11	119	0.4	<0.5	4						Category L
	6.0-6.9M	22	<0.5	13	46	6	81	0.19	<0.5	4						Category L
	7.0-7.9M	58	0.5	36	115	18	271	0.58	1.3	7						Category H
	8.0-8.9M	37	<0.5	22	81	10	185	0.66	0.7	5						Category M
	9.0-9.9M	2	<0.5	4	8	2	10	<0.05	<0.5	<1						Category L
	10.0-10.45	2	<0.5	4	8	2	6	<0.05	<0.5	<1						Category L
MV15	0-0.9M	151	<0.5	45	55	20	147	0.07	3	5	23	<50	<100	16	<0.015	Category H
	1-1.9M	5	<0.5	15	11	10	31	0.05	<0.5	3	<2	91	670	<0.5		Category L
	2.0-2.9M	1	<0.5	3	11	2	7	<0.05	<0.5	1	<2	<50	<100	<0.5		Category L
	3.0-3.9M	1	<0.5	5	12	2	8	<0.05	<0.5	<1	<2	<50	<100	<0.5		Category L
MV16	0-0.9M	15	<0.5	21	21	18	51	0.06	<0.5	2	<2	<50	<100	<0.5	<0.015	Category L
	1.0-1.9M	9	<0.5	24	18	20	53	<0.05	<0.5	4	7	<50	170	<0.5		Category L
	2.0-2.9M	5	<0.5	14	14	12	38	<0.05	<0.5	4	<2	<50	<100	<0.5		Category L
MV17	0-0.9M	258	2	53	327	27	784	0.44	5.6	9	1000	1400	13000	337	<0.015	Category H
	1.0-1.9M	35	<0.5	8	273	4	122	0.08	0.7	1	75	220	6400	2		Category H
MV18	0-0.9M	197	0.7	32	88	16	305	0.14	3.2	4	930	250	1500	275	<0.015	Category H
	1-1.9M	90	0.6	23	106	12	283	0.63	1.5	5	59	180	900	64		Category H
	2-2.9M	16	<0.5	21	65	14	130	1.06	<0.5	7	<2	<50	180	<0.5		Category H
	3-3.9M	4	<0.5	16	12	10	34	0.12	<0.5	5	<2	<50	<100	<0.5		Category L
	4-4.9M	4	<0.5	15	27	9	29	0.07	<0.5	7						Category L
	5-5.9M	3	<0.5	9	19	5	24	<0.05	<0.5	4						Category L
	6-6.9M	4	<0.5	10	21	6	22	<0.05	<0.5	5						Category L
	7-7.13M	<1	<0.5	2	5	<1	<5	<0.05	<0.5	<1						Category L
MV19	0-0.9M	298	1.7	59	197	28	645	1.28	3.7	9	590	320	3000	305		Category H
	1-1.9M	9	<0.5	21	24	13	50	0.07	<0.5	6	<2	<50	120	1		Category L
	2-2.9M	5	<0.5	12	10	8	26	<0.05	<0.5	3	<2	<50	<100	<0.5		Category L
	3-3.9M	4	<0.5	13	9	6	22	<0.05	<0.5	3	<2	<50	<100	<0.5		Category L
	4-4.9M	2	<0.5	8	7	2	10	<0.05	<0.5	3						Category L
	5-5.9M	2	<0.5	4	6	2	6	0.08	<0.5	3						Category L
MV20	0-0.9M	4	<0.5	9	11	6	21	0.06	<0.5	3	<2	<50	<100	<0.5	<0.015	Category L
	1.0-1.9M	1	<0.5	7	23	4	14	<0.05	<0.5	4	<2	<50	<100	<0.5		Category L
	2.0-2.9M	<1	<0.5	7	22	2	11	<0.05	<0.5	4	<2	<50	<100	<0.5		Category L
	3.0-3.4M	<1	<0.5	2	16	<1	11	<0.05	<0.5	1	<2	<50	<100	<0.5		Category L

Notes:

1. Low molecular weight PAHs, that is, acenaphthene, acenaphthylene, anthracene, fluorene, naphthalene and phenanthrene.

2. High molecular weight PAHs, that is, benzo[a]anthracene, benzo[a]pyrene, chrysene, dibenzo[a,h]anthracene, fluoranthene, pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, indeno[1,2,3-c,d]pyrene and benzo[g,h,i]perylene.

3. Values in underline indicate Category M sediment under WBTC No. 3/2000.

4. Values in bold indicate Category H sediment under WBTC No. 3/2000.

5. Values in bold and underline indicate Category H sediment under WBTC No. 3/2000 and that the contaminant level exceeds the LCEL by 10 times.

6.5 Identification of Potential Sources of Impact

6.5.1 The construction activities to be carried out for the proposed Project will result in the generation of a variety of wastes that can be divided into distinct categories based on their composition and ultimate method of disposal. The identified waste types include :

· marine dredged sediment;

· C&D materials (including excavated material);

· chemical wastes; and

· general refuse.

The nature of each type of waste arising is described below, together with an evaluation of the potential environmental impacts associated with these waste arisings.

6.6 Prediction and Evaluation of Environmental Impacts

Marine Dredged Sediment

6.6.1 It is proposed that mud would be left in place at the west and east corners of the WDII reclamation within the Causeway Bay Typhoon Shelter. The other areas of the typhoon shelter would be fully dredged. The total volume of dredged sediment for the WDII reclamation is estimated to be approximately 0.99 Mm³. The estimated volume of contaminated dredged sediment is approximately 0.6 Mm³. The potential environmental effects of the removal of these sediments on water quality have been assessed and presented in Section 5 of this Report.

6.6.2 In order to minimise any potential adverse impacts arising from the dredged marine sediment, the sediment should be dredged, transported and disposed of in a manner that minimises the loss of contaminants either into solution or by resuspension. Mitigation measures to minimise potential environmental impacts are recommended in Section 6.7. It is anticipated that, with the implementation of mitigation measures, no unacceptable impacts will result from the transportation and disposal of the dredged sediment.

Construction and Demolition Materials

6.6.3 C&D material will comprise unwanted materials generated during construction activities and may include:

· wood from formwork and falsework;

· materials packaging and equipment wrappings;

· unusable / surplus concrete / grouting mixes;

· damaged or contaminated surplus construction materials; and

· excavated materials.

6.6.4 Demolition material will be generated from the removal of the Wan Chai ferry piers, west and east bridges at the HKCEC and other existing waterfront structures. Based on the preliminary construction programme, the demolition of the existing ferry piers is scheduled to take place between June and October 2004. The demolition of the west and east bridges at the HKCEC is scheduled to take place between December 2006 and January 2007. The estimated volume of demolition material from removal of Wan Chai ferry piers as well as the west and east bridges at the HKCEC and Hung Hing Road flyover is approximately 17,000 m³. In addition, demolition material will be generated from the removal of the western section of the Causeway Bay typhoon shelter breakwater and RHKYC facilities (such as breakwater, pontoon, workshop), with an estimated volume of approximately 15,100 m³ and 11,900 m³, respectively.

6.6.5 The amount of C&D material expected to be generated will be quantified in the site Waste Management Plan to be prepared by the Contractor. Since the construction activities will be located near the waterfront, improper management of C&D materials or spillage of slurry / grouting mixes may introduce debris and pollutants to the harbour waters, and mitigation measures will be required (refer to Section 6.7).

6.6.6 C&D material generated from the demolition works will be sorted on-site into public fill (which should be re-used on-site as far as possible) and C&D waste (which will require disposal to landfill). All the suitable (inert) material should be broken down to 250 mm in size for reuse as public fill in the WDII reclamation (for filling from +2.5 mPD to the formation level). By reducing the quantity of C&D material requiring off-site disposal, the potential for environmental impacts from the transportation of material by road will also be reduced (such as noise impacts, possible congestion due to increased traffic flows, and dust and exhaust emissions from the haul vehicles). It is recommended that C&D material should be transported from the site by barge wherever possible to reduce impacts from road transportation. The estimated volume of C&D waste requiring off-site disposal to landfill is approximately 5,800 m³.

6.6.7 Excavated materials will mainly arise from the excavation works for the CWB tunnel that will take place upon completion of the diaphragm walls of the tunnel. The excavated material will comprise reclamation fill material that could be reused on-site as fill material for other areas of the WDII reclamation, except those materials, including the residual bentonite slurries, arising from the later stages of excavation works which would require off-site disposal. Considering the inert nature of the fill material, reuse on-site will not result in any unacceptable environmental impact. The amount of residual used bentonite slurry requiring disposal is estimated to be about 75,700 m³.

6.6.8 The excavated material from the excavation for the tunnel box on reclaimed land will be sand fill, of about 500,000 m³. Since a section of the tunnel will also be constructed through existing land, approximately 70,000 m³ of existing ground fill material will also be excavated. The estimated volume of surplus excavated material likely to require off-site disposal is approximately 170,000 m³. This volume arises due to excavation of the sections of the CWB tunnel during the later stages of the project, when filling has been completed in all the reclamation areas. There will therefore be little scope for reuse of this excavated material on-site. Some of this excavated material could be used in the later stages of the project in road abutments and landscaped areas and, depending on the detailed construction interface programming, in the concurrent CWB & IECL project, however, these quantities would be relatively small in relation to the off-site disposal requirement noted above.

6.6.9 Suitable excavated materials generated from the concurrent CWB&IECL project works at Central Interchange and CWB tunnel construction under the CRIII project, which take place at earlier stages of the WDII project, could possibly be reused in the WDII reclamation, depending on the detailed construction interface arrangements at the time.

Chemical Waste

6.6.10 Chemical waste, as defined under the Waste Disposal (Chemical Waste) (General) Regulation, includes any substance being scrap material or unwanted substances specified under Schedule 1 of the Regulation. However, substances likely to be generated by construction activities will, for the most part, arise from the maintenance of equipment. These substances may include::

· scrap batteries or spent acid / alkali from their maintenance;

· used engine oils, hydraulic fluids and waste fuel;

· spent mineral oils / cleaning fluids from mechanical machinery; and

· spent solvents / solutions, some of which may be halogenated, from equipment cleaning activities.

6.6.11 It is not possible to quantify the amount of chemical waste which will arise from the construction activities since it will be highly dependent on the Contractor’s on-site maintenance requirements and the amount of plant utilised. The amount of chemical waste expected to be generated will be quantified in the site Waste Management Plan to be prepared by the Contractor.

6.6.12 Chemical wastes arising during the construction phase may, however, pose serious environmental, health and safety hazards if not stored and disposed of in an appropriate manner as outlined in the Chemical Waste Regulations. These hazards include:

· toxic effects to workers;

· adverse impacts on water quality from spills;

· fire hazards; and

· disruption of sewage treatment works should the chemical waste enter the sewerage system.

6.6.13 Materials classified as chemical wastes will need special handling and storage arrangements before removal for appropriate treatment at the Chemical Waste Treatment Facility (CWTF) at Tsing Yi. Wherever possible, opportunities should be taken to reuse and recycle materials. Mitigation and control requirements for chemical wastes are detailed in Section 6.7. Provided that the handling, storage and disposal of chemical wastes are in accordance with these requirements, adverse environmental impacts should not result.

General Refuse

6.6.14 Throughout construction, the workforce will generate general refuse comprising food scraps, waste paper, empty containers, etc. Release of general refuse into marine waters should not be permitted as introduction of these wastes is likely to have detrimental effects on water quality in the area. Rapid and effective collection of site wastes will be required to prevent waste materials being blown around by wind, flushed or leached into the marine environment, and odour nuisance. The work sites may also attract pests and vermin if the waste storage area is not well maintained and cleaned regularly. Disposal of refuse at sites other than approved waste transfer or disposal facilities can also result in similar impacts.

6.6.15 It is anticipated that there will be a maximum of 300 construction workers working simultaneously at the construction site. Based on a generation rate of 0.65 kg per worker per day, the maximum daily arisings of general refuse during the construction period will be approximately 200 kg. With the implementation of waste management practices at the site (as recommended in Section 6.7), adverse environmental impacts are not expected to arise from the storage, handling and transportation of refuse.

6.7 Mitigation Measures

Marine Sediments

6.7.1 The basic requirements and procedures for dredged mud disposal are specified under the WBTC No. 3/2000. The management of the dredging, use and disposal of marine mud is monitored by the MFC, while the licensing of marine dumping is the responsibility of the Director of Environmental Protection (DEP).

6.7.2 The dredged marine sediments will be loaded onto barges and transported to designated disposal sites depending on their level of contaminants. As discussed in Section 6.4, the majority of the marine sediment to be dredged is Category H (biological test not required). In accordance with the WBTC No. 3/2000, the contaminated material must be dredged and transported with great care, and the mitigation measures recommended in Section 5.8 of this Report should be strictly followed. Furthermore, the dredged contaminated sediment must be effectively isolated from the environment upon final disposal and shall be disposed of at the East Sha Chau Contaminated Mud Pits that is designated for the disposal of contaminated mud in Hong Kong.

6.7.3 At vibrocores MV11, MV12, MV17, MV18 and MV19 located within the Causeway Bay typhoon shelter, the reported contaminant level of Total PCBs in the top 1 to 2 m of sediment exceeds the LCEL by 10 times. To determine the disposal requirements of the dredged sediment at these locations, it is likely that Tier III biological screening (dilution test) will be required for the sediment sampling and testing to be carried out in the further ground investigation works at the design phase of the Project. Biological screening will also be required for any identified Category M sediment in the further ground investigation works for the Project. The need for any special treatment / disposal procedures for dredged sediments from the Causeway Bay typhoon shelter will be examined in detail at the detailed design stage of the Project, as necessary, based on the results of biological screening.

6.7.4 At this stage, based on the existing vibrocore sampling results, it is estimated that some 2,100 m³ of PCB-contaminated sediments may require pre-treatment or special disposal arrangements. Pre-treatment by techniques such as bioremediation, dechlorination, soil washing, solvent extraction and thermal desorption have been examined. Treatability studies would be needed to confirm the suitability of the pre-treatment process and material sizing and dewatering may also be required. An off-site treatment facility would need to be established. For these reasons, especially in view of the relatively small amount of contaminated sediments involved, and given the possible consequential implementation implications for the project, pre-treatment is not considered suitable for the WDII project. It has therefore been agreed with EPD that special disposal arrangements, rather than pre-treatment, would be appropriate provided there would be negligible loss of sediment to the marine environment during the dumping operations.

6.7.5 To cater for the possibility that some of the Category H sediments may fail the Tier III biological test, a review of possible special disposal arrangements for the contaminated sediment has been carried out with the objective of keeping the loss of sediment to the surrounding marine environment to a negligible extent. Several options may be suitable, but the method pursued as having the least potential for loss of contaminants to the marine environment is by containment of the sediments in geosynthetic containers. A feasible containment method is proposed whereby the dredged sediments are sealed in geosynthetic containers and, at the disposal site, the containers would be dropped into the designated contaminated mud pit where they would be covered by further mud disposal and later by the mud pit capping, thereby meeting the requirements for fully confined mud disposal. The technology is readily available for the manufacture of the geosynthetic containers to the project-specific requirements. Similar disposal methods have been used for projects in Europe and the USA (for example, geosynthetic fabric containers have been used to contain contaminated dredged sediment at Marina Del Rey in California) and the issues of fill retention by the geosynthetic fabrics, possible rupture of the containers and sediment loss due to impact of the container on the seabed have been addressed.^([2]) Nevertheless, field trials are recommended to be undertaken during the detailed design site investigation stage (using uncontaminated mud) to establish the optimum handling method for this approach. The details of the disposal methodology will therefore be confirmed during the detailed design stage, prior to construction.

6.7.6 It will be the responsibility of the Contractor to satisfy the appropriate authorities that the contamination levels of the marine sediment to be dredged have been analysed and recorded. According to the WBTC No. 3/2000, this will involve the submission of a formal Sediment Quality Report to the DEP, at least 3 months prior to the dredging contract being tendered.

6.7.7 During transportation and disposal of the dredged marine sediments, the following measures should be taken to minimise potential impacts on water quality.

· Bottom opening of barges shall be fitted with tight fitting seals to prevent leakage of material. Excess material shall be cleaned from the decks and exposed fittings of barges and hopper dredgers before the vessel is moved.

· Monitoring of the barge loading shall be conducted to ensure that loss of material does not take place during transportation. Transport barges or vessels shall be equipped with automatic self-monitoring devices as specified by the DEP.

Good Site Practices and Waste Reduction Measures

6.7.8 It is not anticipated that adverse waste management related impacts would arise, provided that good site practices are strictly followed. Recommendations for good site practices during the construction activities include:

· nomination of an approved personnel, such as a site manager, to be responsible for good site practices, arrangements for collection and effective disposal to an appropriate facility, of all wastes generated at the site;

· training of site personnel in proper waste management and chemical handling procedures;

· provision of sufficient waste disposal points and regular collection for disposal;

· appropriate measures to minimise windblown litter and dust during transportation of waste by either covering trucks or by transporting wastes in enclosed containers;

· separation of chemical wastes for special handling and appropriate treatment at the CWTF;

· regular cleaning and maintenance programme for drainage systems, sumps and oil interceptors; and

· a recording system for the amount of wastes generated, recycled and disposed of (including the disposal sites).

6.7.9 In order to monitor the disposal of C&D waste at landfills and to control fly tipping, a trip-ticket system should be included as one of the contractual requirements and implemented by an Environmental Team undertaking the Environmental Monitoring and Audit work. An Independent Environmental Checker should be responsible for auditing the results of the system.

6.7.10 Good management and control can prevent the generation of significant amount of waste. Waste reduction is best achieved at the planning and design stage, as well as by ensuring the implementation of good site practices. Recommendations to achieve waste reduction include:

· segregation and storage of different types of waste in different containers, skips or stockpiles to enhance reuse or recycling of materials and their proper disposal;

· to encourage collection of aluminium cans by individual collectors, separate labelled bins shall be provided to segregate this waste from other general refuse generated by the work force;

· any unused chemicals or those with remaining functional capacity shall be recycled;

· use of reusable non-timber formwork, such as in casting the tunnel box sections, to reduce the amount of C&D material;

· prior to disposal of C&D waste, it is recommended that wood, steel and other metals shall be separated for re-use and / or recycling to minimise the quantity of waste to be disposed of to landfill;

· proper storage and site practices to minimise the potential for damage or contamination of construction materials; and

· plan and stock construction materials carefully to minimise amount of waste generated and avoid unnecessary generation of waste.

6.7.11 In addition to the above good site practices and waste reduction measures, specific mitigation measures are recommended below for the identified waste arisings to minimise environmental impacts during handling, transportation and disposal of these wastes. The transportation of these wastes by barge to the disposal location is recommended, as far as practicable, in order to reduce potential noise and air quality impacts from road transportation.

Construction Waste and General Refuse

6.7.12 A collection area should be provided where wastes can be stored and loaded prior to removal from site. An enclosed and covered area is preferred to reduce the occurrence of 'wind blow' light material. If an open area is unavoidable for the storage or loading / unloading of wastes, then the area should be bunded and all the polluted surface run-off collected within this area should be diverted into sewers.

Chemical Wastes

6.7.13 After use, chemical wastes (for example, cleaning fluids, solvents, lubrication oil and fuel) should be handled according to the Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes. Spent chemicals should be stored and collected by an approved operator for disposal at the CWTF or other licensed facility in accordance with the Chemical Waste (General) Regulation.

6.7.14 Any service shop and minor maintenance facilities should be located on hard standings within a bunded area, and sumps and oil interceptors should be provided. Maintenance of vehicles and equipment involving activities with potential for leakages and spillage shall only be undertaken within areas appropriately equipped to control these discharges.

Construction and Demolition Material

6.7.15 The C&D material should be sorted on-site into inert C&D material (that is, public fill) and C&D waste. Considering that a large quantity of C&D material will be generated from the demolition works and in order to minimise the impact resulting from collection and transportation of material for off-site disposal, it is recommended that the inert C&D material should be re-used on-site in the reclamation works. All the suitable (inert) material should be broken down to 250 mm in size for reuse as public fill in the WDII reclamation. C&D waste, such as wood, glass, plastic, steel and other metals should be reused or recycled and, as a last resort, disposed of to landfill. It is recommended that a suitable area be designated to facilitate the sorting process and a temporary stockpiling area will be required for the separated materials. Bentonite slurries used in diaphragm wall and bore-pile construction should be reconditioned and reused wherever practicable. The disposal of residual used bentonite slurry should follow the good practice guidelines stated in ProPECC PN 1/94 “Construction Site Drainage” and listed as follows:

· If the disposal of a certain residual quantity cannot be avoided, the used slurry may be disposed of at the marine spoil grounds subject to obtaining a marine dumping licence from EPD on a case-by-case basis.

· If the used bentonite slurry is intended to be disposed of through the public drainage system, it should be treated to the respective effluent standards applicable to foul sewers, storm drains or the receiving waters as set out in the Technical Memorandum of Standards for Effluents Discharged into Drainage and Sewerage Systems, Inland and Coastal Waters.

6.7.16 Table 6.4 provides a summary of the various waste types likely to be generated during the reclamation works, together with the recommended handling and disposal methods.

Table 6.4 Summary of Waste Handling Procedures and Disposal Routes

Waste Type	Handling	Disposal
C&D Material from Demolition Works	Sort on-site into : · Inert C&D material (public fill) · C&D waste	Suitable material broken down to 250 mm in size for reuse as public fill in WDII reclamation (approx. 44,000m^3) Off-site disposal to landfill (approx. 5,800 m^3)
C&D Material from Excavation Works	Segregate inert fill material to avoid contamination from other waste arisings	Reuse on-site as far as practicable (approx. 400,000 m^3) Surplus fill material to be disposed off-site (approx. 170,000 m^3)
Dredged Sediments*	Contaminated: techniques to minimise resuspension (close grabs, tight seal on barges, controlled loading and transfer)	MFC contaminated mud pit (approx. 600,000 m^3)
	Uncontaminated: minimise resuspension (close grabs, tight seal on barges, controlled loading and transfer)	MFC gazetted marine disposal ground (approx. 400,000 m^3)
Chemical Wastes	Recycle on-site or by licensed companies Stored on-site within suitably designed containers	Chemical Waste Treatment Facility
General Refuse	Provide on-site refuse collection facilities	Refuse station for compaction and containerisation and then to landfill

Notes:

* Details of handling procedures and disposal methods for dredged sediment should refer to Section 5.8. The need for special disposal procedures for dredged contaminated sediments from the Causeway Bay typhoon shelter will be examined in detail at the design stage of the Project, as necessary, based on the sediment testing results of the further ground investigation works.

6.8 Evaluation of Residual Impacts

6.8.1 With the implementation of the recommended mitigation measures for the handling, transportation and disposal of the identified waste arisings, no residual impact is anticipated during the construction of the proposed Project.

6.9 Environmental Audit

6.9.1 Waste management will be the contractor’s responsibility to ensure that all wastes produced during the construction of the Project are handled, stored and disposed of in accordance with good waste management practices and EPD’s regulations and requirements. The mitigation measures recommended in Section 6.7 should form the basis of the site Waste Management Plan to be developed by the Contractor in the construction stage.

6.9.2 It is recommended that the waste arisings generated during the construction activities should be audited periodically to determine if wastes are being managed in accordance with approved procedures and the site Waste Management Plan. The Waste Management Plan prepared by the Contractor has to be submitted to the Engineer for approval on the advice of the EPD. The audits should look at all aspects of waste management including waste generation, storage, recycling, transport and disposal. An appropriate audit programme would be to undertake a first audit near the commencement of the construction works, and then to audit quarterly thereafter.

6.10 Conclusion

6.10.1 A review of the sediment quality data from the marine ground investigation works indicates that the majority of the marine sediments to be dredged in the proposed WDII area are classified as Category H (biological test not required). The dredged sediment will therefore not be suitable for open sea disposal. With the implementation of the mitigation measures detailed in Section 6.7 in accordance with the requirements of WBTC No. 3/2000, no residual impact is predicted.

6.10.2 To determine the disposal requirements of the Category H sediment (with Total PCBs exceeding 10 times the LCEL) identified within the Causeway Bay typhoon shelter, Tier III biological screening (dilution test) would be required for the sediment sampling and testing to be carried out in the further ground investigation works at the design phase of the Project. Biological screening will also be required for any identified Category M sediment in the further ground investigation works for the Project. The need for any special treatment / disposal procedures for dredged sediments from the Causeway Bay typhoon shelter will be examined in detail at the design stage of the Project, as necessary, based on the results of biological screening. It has been agreed with EPD that special disposal arrangements, rather than pre-treatment, would be acceptable provided there would be negligible loss of sediment to the marine environment during the dumping operations. A review of possible disposal arrangements has recommended containment of the contaminated sediments during dumping to prevent any release of material to the marine environment. Field trials are recommended to be undertaken during the detailed design stage (using uncontaminated mud) to establish the optimum handling method.

6.10.3 Wastes generated by the construction activities are likely to include C&D materials (including excavated material and demolition material), general refuse and chemical waste. Provided that these identified waste arisings are handled, transported and disposed of using approved methods and that the recommended good site practices are strictly followed, adverse environmental impacts are not anticipated.

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([1]) “C&D material” contains a mixture of inert and non-inert material. The inert portion is the “public fill” and the non-inert portion is the “C&D waste”.

(2) (i) Young, H. M. et al. “The migration of contaminants through geosynthetic fabric containers utilized in dredging operation”. Engineering Geology, 53 (1999), 167-176;

(ii) Fleischer, P., Bowles, F. A. “Turbidity currents generated by seafloor impact of geotextile fabric containers”. Applied Ocean Research, 21 (1999) 215-217;

(iii) Valent, P. J. et al. “Engineering concepts for the placement of wastes on the abyssal seafloor”. Journal of Marine Systems, 14 (1998) 273-288.