Ÿ Environmental Impact Assessment Ordinance (EIAO) (Cap. 499), Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM), Section 3 (Potential Contaminated Land Issues) of Annex 19 of the ‘Guidelines for Assessment of Impact on Sites of Cultural Heritage and Other Impacts’
Ÿ The Guidance Note for Contaminated Land Assessment and Remediation (Guidance Note) sets out the requirements for proper assessment and management of potentially contaminated sites such as oil installations (e.g. oil depots, petrol filling stations), gas works, power plants, shipyards/boatyards, chemical manufacturing/processing plants, steel mills/metal workshops, car repairing/dismantling workshops and scrap yards.
Ÿ The Practice Guide for Investigation and Remediation of Contaminated Land (Practice Guide). This guide outlines typical investigation methods and remediation strategies for the range of potential contaminants typically encountered in Hong Kong.
Ÿ The Guidance Manual for Use of Risk-Based Remediation Goals for Contaminated Land Management (Guidance Manual) presents the risk based approach for contamination assessment and instructions for comparison of soil and groundwater data with Risk-Based Remediation Goals (RBRGs) for 54 chemicals of concern commonly found in Hong Kong. The RBRGs were derived to suit Hong Kong conditions and were designed to protect the health of people who could potentially be exposed to land impacted by chemicals under four broad post-restoration land use categories. RBRGs also serve as the remediation targets if remediation is necessary. The RBRGs for soil and groundwater are given in Tables 8.1 and 8.2.
Table 8.1 Risk-Based Remediation Goals (RBRGs) for Soil
& Soil Saturation Limit
|
Chemical |
Risk-Based Remediation Goals (RBRGs) for Soil |
Soil Saturation Limit (Csat) |
|||
|
Urban Residential |
Rural Residential |
Industrial |
Public Parks |
||
|
(mg/kg) |
(mg/kg) |
(mg/kg) |
(mg/kg) |
(mg/kg) |
|
|
VOCs |
|||||
|
Acetone |
9,590 |
4,260 |
10,000* |
10,000* |
*** |
|
Benzene |
0.704 |
0.279 |
9.21 |
42.2 |
336 |
|
Bromodichloromethane |
0.317 |
0.129 |
2.85 |
13.4 |
1,030 |
|
2-Butanone |
10,000* |
10,000* |
10,000* |
10,000* |
*** |
|
Chloroform |
0.132 |
0.0529 |
1.54 |
253 |
1,100 |
|
Ethylbenzene |
709 |
298 |
8,240 |
10,000* |
138 |
|
Methyl tert-Butyl Ether |
6.88 |
2.80 |
70.1 |
505 |
2,380 |
|
Methylene Chloride |
1.30 |
0.529 |
13.9 |
128 |
921 |
|
Styrene |
3,220 |
1,540 |
10,000* |
10,000* |
497 |
|
Tetrachloroethene |
0.101 |
0.0444 |
0.777 |
1.84 |
97.1 |
|
Toluene |
1,440 |
705 |
10,000* |
10,000* |
235 |
|
Trichloroethene |
0.523 |
0.211 |
5.68 |
69.4 |
488 |
|
Xylenes (Total) |
95.0 |
36.8 |
1,230 |
10,000* |
150 |
|
SVOCs |
|||||
|
Acenaphthene |
3,510 |
3,280 |
10,000* |
10,000* |
60.2 |
|
Acenaphthylene |
2,340 |
1,510 |
10,000* |
10,000* |
19.8 |
|
Anthracene |
10,000* |
10,000* |
10,000* |
10,000* |
2.56 |
|
Benzo(a)anthracene |
12.0 |
11.4 |
91.8 |
38.3 |
-- |
|
Benzo(a)pyrene |
1.20 |
1.14 |
9.18 |
3.83 |
-- |
|
Benzo(b)fluoranthene |
9.88 |
10.1 |
17.8 |
20.4 |
-- |
|
Benzo(g,h,i)perylene |
1,800 |
1,710 |
10,000* |
5,740 |
-- |
|
Benzo(k)fluoranthene |
120 |
114 |
918 |
383 |
-- |
|
Bis-(2-Ethylhexyl)phthalate |
30.0 |
28.0 |
91.8 |
94.2 |
-- |
|
Chrysene |
871 |
919 |
1,140 |
1,540 |
-- |
|
Dibenzo(a,h)anthracene |
1.20 |
1.14 |
9.18 |
3.83 |
-- |
|
Fluoranthene |
2,400 |
2,270 |
10,000* |
7,620 |
-- |
|
Fluorene |
2,380 |
2,250 |
10,000* |
7,450 |
54.7 |
|
Hexachlorobenzene |
0.243 |
0.220 |
0.582 |
0.713 |
-- |
|
Indeno(1,2,3-cd)pyrene |
12.0 |
11.4 |
91.8 |
38.3 |
-- |
|
Naphthalene |
182 |
85.6 |
453 |
914 |
125 |
|
Phenanthrene |
10,000* |
10,000* |
10,000* |
10,000* |
28.0 |
|
Phenol |
10,000* |
10,000* |
10,000* |
10,000* |
7,260 |
|
Pyrene |
1,800 |
1,710 |
10,000* |
5,720 |
-- |
|
Metals |
|||||
|
Antimony |
29.5 |
29.1 |
261 |
97.9 |
-- |
|
Arsenic |
22.1 |
21.8 |
196 |
73.5 |
-- |
|
Barium |
10,000* |
10,000* |
10,000* |
10,000* |
-- |
|
Cadmium |
73.8 |
72.8 |
653 |
245 |
-- |
|
Chromium III |
10,000* |
10,000* |
10,000* |
10,000* |
-- |
|
Chromium VI |
221 |
218 |
1,960 |
735 |
-- |
|
Cobalt |
1,480 |
1,460 |
10,000* |
4,900 |
-- |
|
Copper |
2,950 |
2,910 |
10,000* |
9,790 |
-- |
|
Lead |
258 |
255 |
2,290 |
857 |
-- |
|
Manganese |
10,000* |
10,000* |
10,000* |
10,000* |
-- |
|
Mercury |
11.0 |
6.52 |
38.4 |
45.6 |
-- |
|
Molybdenum |
369 |
364 |
3,260 |
1,220 |
-- |
|
Nickel |
1,480 |
1,460 |
10,000* |
4,900 |
-- |
|
Tin |
10,000* |
10,000* |
10,000* |
10,000* |
-- |
|
Zinc |
10,000* |
10,000* |
10,000* |
10,000* |
-- |
|
Dioxins / PCBs |
|||||
|
Dioxins (I-TEQ) |
0.001 |
0.001 |
0.005 |
0.001 |
-- |
|
PCBs |
0.236 |
0.226 |
0.748 |
0.756 |
-- |
|
Petroleum Carbon
Ranges |
|||||
|
C6 - C8 |
1,410 |
545 |
10,000* |
10,000* |
1,000 |
|
C9 - C16 |
2,240 |
1,330 |
10,000* |
10,000* |
3,000 |
|
C17 - C35 |
10,000* |
10,000* |
10,000* |
10,000* |
5,000 |
|
Other Inorganic
Compounds |
|||||
|
Cyanide, free |
1,480 |
1,460 |
10,000* |
4,900 |
-- |
|
Organometallics |
|||||
|
TBTO |
22.1 |
21.8 |
196 |
73.5 |
-- |
Notes:
(1) For
Dioxins, the cleanup levels in USEPA Office of Solid Waste and Emergency
Response (OSWER) Directive of 1998 have been adopted. The OSWER Directive value
of 1 ppb for residential use has been applied to the scenarios of "Urban
Residential", "Rural Residential", and "Public Parks",
while the low end of the range of values for industrial, 5 ppb, has been
applied to the scenario of "industrial".
(2) Soil
saturation limits for petroleum carbon ranges taken from the Canada-Wide
Standards for Petroleum Hydrocarbons in Soil, CCME 2000.
(3) *
indicates a 'ceiling limit' concentration.
(4) ***
indicates that the Csat value exceeds the 'ceiling limit' therefore the RBRG
applies.
Table 8.2 Risk-Based
Remediation Goals (RBRGs) for Groundwater and Solubility Limit
|
Chemical |
Risk-Based Remediation Goals
(RBRGs) for Groundwater |
Groundwater Solubility Limit |
||
|
Urban Residential |
Rural Residential |
Industrial |
||
|
(mg/L) |
(mg/L) |
(mg/L) |
(mg/L) |
|
|
VOCs |
||||
|
Acetone |
10,000* |
10,000* |
10,000* |
*** |
|
Benzene |
3.86 |
1.49 |
54.0 |
1,750 |
|
Bromodichloromethane |
2.22 |
0.871 |
26.2 |
6,740 |
|
2-Butanone |
10,000* |
10,000* |
10,000* |
*** |
|
Chloroform |
0.956 |
0.382 |
11.3 |
7,920 |
|
Ethylbenzene |
1,020 |
391 |
10,000* |
169 |
|
Methyl
tert-Butyl Ether |
153 |
61.1 |
1,810 |
*** |
|
Methylene
Chloride |
19.0 |
7.59 |
224 |
*** |
|
Styrene |
3,020 |
1,160 |
10,000* |
310 |
|
Tetrachloroethene |
0.250 |
0.0996 |
2.95 |
200 |
|
Toluene |
5,110 |
1,970 |
10,000* |
526 |
|
Trichloroethene |
1.21 |
0.481 |
14.2 |
1,100 |
|
Xylenes
(Total) |
112 |
43.3 |
1,570 |
175 |
|
SVOCs |
||||
|
Acenaphthene |
10,000* |
7,090 |
10,000* |
4.24 |
|
Acenaphthylene |
1,410 |
542 |
10,000* |
3.93 |
|
Anthracene |
10,000* |
10,000* |
10,000* |
0.0434 |
|
Benzo(a)anthracene |
-- |
-- |
-- |
-- |
|
Benzo(a)pyrene |
-- |
-- |
-- |
-- |
|
Benzo(b)fluoranthene |
0.539 |
0.203 |
7.53 |
0.0015 |
|
Benzo(g,h,i)perylene |
-- |
-- |
-- |
-- |
|
Benzo(k)fluoranthene |
-- |
-- |
-- |
-- |
|
Bis-(2-Ethylhexyl)phthalate |
-- |
-- |
-- |
-- |
|
Chrysene |
58.1 |
21.9 |
812 |
0.0016 |
|
Dibenzo(a,h)anthracene |
-- |
-- |
-- |
-- |
|
Fluoranthene |
10,000* |
10,000* |
10,000* |
0.206 |
|
Fluorene |
10,000* |
10,000* |
10,000* |
1.98 |
|
Hexachlorobenzene |
0.0589 |
0.0234 |
0.695 |
6.20 |
|
Indeno(1,2,3-cd)pyrene |
-- |
-- |
-- |
-- |
|
Naphthalene |
61.7 |
23.7 |
862 |
31.0 |
|
Phenanthrene |
10,000* |
10,000* |
10,000* |
1.00 |
|
Phenol |
-- |
-- |
-- |
-- |
|
Pyrene |
10,000* |
10,000* |
10,000* |
0.135 |
|
Metals |
||||
|
Antimony |
-- |
-- |
-- |
-- |
|
Arsenic |
-- |
-- |
-- |
-- |
|
Barium |
-- |
-- |
-- |
-- |
|
Cadmium |
-- |
-- |
-- |
-- |
|
Chromium
III |
-- |
-- |
-- |
-- |
|
Chromium
VI |
-- |
-- |
-- |
-- |
|
Cobalt |
-- |
-- |
-- |
-- |
|
Copper |
-- |
-- |
-- |
-- |
|
Lead |
-- |
-- |
-- |
-- |
|
Manganese |
-- |
-- |
-- |
-- |
|
Mercury |
0.486 |
0.184 |
6.79 |
-- |
|
Molybdenum |
-- |
-- |
-- |
-- |
|
Nickel |
-- |
-- |
-- |
-- |
|
Tin |
-- |
-- |
-- |
-- |
|
Zinc |
-- |
-- |
-- |
-- |
|
PCBs |
||||
|
Dioxins
(I-TEQ) |
-- |
-- |
-- |
-- |
|
PCBs |
0.433 |
0.171 |
5.11 |
0.031 |
|
Petroleum Carbon Ranges |
||||
|
C6
- C8 |
82.2 |
31.7 |
1,150 |
5.23 |
|
C9
- C16 |
714 |
276 |
9,980 |
2.80 |
|
C17
- C35 |
12.8 |
4.93 |
178 |
2.80 |
|
Other Inorganic Compounds |
||||
|
Cyanide, free |
-- |
-- |
-- |
-- |
|
Organometallics |
||||
|
TBTO |
-- |
-- |
-- |
-- |
Notes:
(1)
Blank indicates that RBRG could not be calculated because the toxicity
or physical/chemical values were unavailable, or the condition of Henry's Law
Constant > 0.00005 was not met for the inhalation pathway.
(2) Water solubilities for Petroleum
Carbon Range aliphatic C9-C16 and greater than C16 generally are considered to
be effectively zero and therefore the aromatic solubility for C9-C16 is used.
(3) * indicates a 'ceiling limit'
concentration.
(4) *** indicates that the
solubility limit exceeds the 'ceiling limit' therefore the RBRG applies.
Ÿ Desktop study to review the current and
historical land uses; and
Ÿ Site inspection to identify potentially
contaminated areas as necessary.
Ÿ Aerial photographs from Survey and Mapping
Office of Lands Department;
Ÿ Information of chemical waste producer
registration and spillage or release of chemical and/or chemical wastes from
Environmental Protection Department (EPD);
Ÿ Information of dangerous goods from Fire
Services Department (FSD);
Ÿ Photographs from site inspection; and
Ÿ Relevant approved EIA report
Acquistition of Information
from Relevant Government Departments
Environmental Protection Department
Fire Services Department
Review
of Aerial Photographs
Table 8.3 Review of Aerial Photographs
|
Sites |
Year |
Photograph Reference No. |
|
J/O Lin Tak Road / Sau
Mau Ping Road |
2014 |
CS53539 |
|
J/O Clear Water Bay
Road / On Sau Road and J/O Clear Water Bay Road / New Clear Water Bay Road |
2014 |
CS53546 |
|
J/O New Clear Water
Bay Road near Shun Lee Tsuen Road |
2014 |
CS49232 |
Site
Inspection