12 ENVIRONMENGTAL MONITORING & AUDIT REQUIREMENTs
12.1.1 This section summarizes the findings in the EIA and evaluates the need for environmental monitoring and audit (EM&A) in construction and operational phases. The aim of EM&A is to continuously monitor the changes of environmental parameters and the effectiveness of mitigation. This helps early identification of unacceptable environmental deterioration and allows formulation of rectification work at an early stage.
12.1.2 Methodology and requirement of monitoring work are detailed in a standalone Environmental Monitoring and Audit Manual (EM&A Manual).
12.2.1 With proper implementation of dust suppression measures, construction air quality impact is anticipated to be acceptable. Regular air quality monitoring should be carried out at designated monitoring stations to ensure that relevant air quality standard can be met.
12.2.2 Weekly site audit should be carried out to check the implementation status of the recommended air quality impact mitigation measures throughout the construction period.
12.2.3 Based on the modelling results, odour levels at representative air sensitive receivers (ASRs) in operational phase are far below the limit. No monitoring or audit is proposed.
12.3.1 Based on the modelling results, no noise exceedance at noise sensitive receivers (NSRs) in construction phase is anticipated if mitigation measures are implemented properly. Regular noise monitoring should be carried out at designated monitoring stations to ensure that relevant noise standard can be met.
12.3.2 Weekly site audit should be carried out to check the implementation status of the recommended noise impact mitigation measures throughout the construction period.
12.3.3 Most of the noisy equipment in the sewage treatment plant are fully enclosed underground or enclosed by concrete structure. Together with the noise reduction due to the distance between the sewage treatment plant and the nearest noise sensitive receiver (NSR), operational noise impact is anticipated to be acceptable. No monitoring or audit is proposed.
12.4.1 Dredging works at the proposed diffuser location will be confined within fully-enclosed cofferdam. No leakage of suspended solids into water column is anticipated. Regular water quality monitoring should be carried out at designated monitoring stations before and during cofferdam installation works, throughout dredging works, and during cofferdam extraction works to ensure that relevant water quality standard can be met. No adverse construction water quality impact is expected if the mitigation measures are implemented properly.
12.4.2 Weekly site audit should be carried out to check the implementation status of the recommended water quality impact mitigation measures throughout the construction period.
12.4.3 The computational model concluded no substantial change in water quality at water sensitive receivers (WSRs) during normal operation of the Project. However due to sensitivity of fish culture zone, corals and amphioxus to water quality change in the enclosed bay, marine water quality monitoring shall be conducted in the first year of operation to ensure that effluent discharge from the Project will not result in adverse impact on these WSRs. In addition, effluent testing should be carried out at intervals stipulated in the discharge license issued by the EPD to ensure compliance with the requirement.
12.5.1 In addition to habitat loss, indirect impact on terrestrial ecology due to water deterioration from surface runoff and noise disturbance from plant equipment is expected. With proper implementation of mitigation measures, residual impact is expected to be acceptable. No specific monitoring is required for terrestrial ecology.
12.5.2 Weekly site audit should be carried out to check the implementation status of the recommended protection measures of the protected shrub throughout the construction period.
12.6.1 The proposed Project will cause minor habitat loss of muddy seabed. Dredging works and the suspended solids generated will be confined within the fully-enclosed cofferdam. During both construction and operational phases, no substantial change in water quality at where corals and amphioxus inhibited is expected. With implementation of mitigation measures on the protection of water quality, residual impact is expected to be acceptable.
12.6.2 Monitoring at these sensitive receivers will be conducted as part of the water quality monitoring in the construction and operational phases. No specific monitoring is required for marine ecology.
12.7.1 No direct impact on the Po Toi O Fish Culture Zone and Artificial Reefs in the Study Area is expected. About 1,920 m2 of fishing ground and 500 m2 of benthic spawning ground will be affected. Except the 5 m2 benthic spawning ground will be lost permanently, other impacted area will only be affected in construction phase temporarily (reversible impact). No significant water quality impact is expected during construction or operational phases with proper implementation of water quality mitigation measures.
12.7.2 Water quality monitoring at the Po Toi O Fish Culture Zone will be conducted as part of monitoring and audit programme on water quality in the construction and operational phases. No specific monitoring is required for fisheries.
12.8.1 Waste produced from land-based works in construction phase includes C&D (construction and demolition) materials, chemical waste and general refuse. C&D materials will be generated from excavation, site formation and demolition. Chemical waste will be produced from maintenance of equipment and used bentonite slurry from horizontal directional drilling, while general refuse will be generated by workers.
12.8.2 Waste produced from marine-based works in construction phase includes marine sediment from dredging. Sediment Sampling and Testing Plan (SSTP) has been submitted to EPD as required under the Study Brief. Marine sediment at the proposed dredging site belongs to Cat. L. According to ETWB TC(W) No. 34/2002, the sediment shall be dumped at open sea disposal ground designated by Marine Fill Committee.
12.8.3 No adverse construction waste impact is expected if the mitigation measures are implemented properly. The contractor should formulate waste management measures on waste minimization, storage, handling and disposal in a Waste Management Plan as part of Environmental Management Plan.
12.8.4 Weekly site audit should be carried out to check the implementation status of the recommended waste management measures throughout the construction period.
12.8.5 Operation of the sewage treatment plant will generate sludge, debris from screening, worn carbon filter in deodouring unit and general refuse from staff. No adverse waste impact is expected if the mitigation measures are implemented properly. No monitoring or audit is required.
12.9.1
With
implementation of mitigation measures, minor landscape
and visual impact is expected due to dredging work in open sea, construction of
the STP and pipelines on land, and the loss of existing trees and vegetation
at the sewage treatment plant site. Due to the relatively small scale of the
proposed Project, none of the LRs, LCAs or VSRs will experience substantial
impacts.
12.9.2
Regular site audit should be performed to check the implementation
status of recommended landscape and visual impact mitigation measures
throughout the construction
period.
12.9.3
During the operational phase, the newly built sewage treatment plant
will be a source of landscape and visual impact. Residual impacts are considered
acceptable after mitigation.
12.9.4
Regular monitoring should be
undertaken in construction
and operational phases to ensure that the landscape and visual mitigation measures have
been implemented, are effective and are being managed and maintained. This shall be carried out by the Registered Landscape Architect engaged by the Contractor during construction
phase and the first year
after construction (a common practice in EIA) to check that intended mitigation
effects are realised. During this
period, the Contractor shall take good care of the trees through regular
horticultural operation (e.g. watering and pruning). Trees that do not survive
shall be replaced. This can help the trees to establish and have higher chance
of growing to maturity for the intended landscape effect. At the end of the 1-year
establishment period after construction, the STP site and trees shall be handed
over to the project proponent (building operator) for future management and
maintenance.
12.10.1
One
Grade 3 historic building (Hung Shing Temple), two built heritages and six
landscape features were the built heritage resources identified in the Study Area. There will be no direct damage to any of the built heritage resources. Regular condition survey and vibration and
settlement monitoring should be conducted to ensure that these sensitive
receivers will not be damaged during construction phase.
12.10.2
Regular
site audit should be performed to check the implementation status of the
recommended mitigation measures throughout construction period.
12.10.3
No
operational phase impact is expected. Therefore, no monitoring or audit is
proposed.