Concerns about tunnelling for Penang’s ‘monster highway’

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Make sure you head down to Spice for the ‘town hall’ meeting with the Department of Environment on Thursday, 22 20 September at 8pm regarding the EIA for the RM8bn 19.5km six-lane Pan Island Link, which includes 10.1km of tunnels.

Soil scientist Dr Kam Suan Pheng writes in response to a letter that appeared in the press:

I refer to the article posted in FMT by reader CN Ng on 01 September 2018 titled “So what if there are faults in granite? You can still build tunnel”.

As I pointed out at the beginning, the main purpose of my talk was to share with the public the findings of the environmental impact assessment (EIA) report for the Pan Island Link 1 (PIL1) highway project. The EIA report is a professional piece of work that is to be evaluated on its own merits and it is pertinent to flag issues that are revealed but not sufficiently addressed by the EIA study.

All the points concerning the geological and geotechnical aspects raised were extracted from the EIA report, and to quote more extensively from it:

On page 7-34 the EIA Report identifies the geology and geotechnical concerns to include:

Mass earth movements given the occurrence of highly fractured/jointed granite bedrock and fault zones; the lateral alignment of PIL1 cuts across at least two major fault lines; and

Ground movements and vibrations occurring during and after construction may affect natural ground and nearby existing structures.

In the executive summary, it is stated:

The construction of tunnels may cause a deformation of the soils that may trigger a collapse and subsidence. Areas that intersect with fault zones are highly fractured and vulnerable to collapse. This can damage both, the work under construction and existing nearby structures such as condominiums, the Kek Lock Si Temple, the Air Itam Dam and the Bukit Bendera complex.” (page ES-18), with the conclusion that the magnitude and duration of impact from construction of main tunnels (drill-blast method) is rated as “Medium to High” (Table 7.1 page ES-33).

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Page 7-36 of the EIA report tabulates the potentially significant impacts associated with tunnel construction conditions and activities:

Condition/Activity:

The tunnel portals are at areas known to have granitic residual soil and/or colluvium with a high percentage of boulders. Occurrence of highly fractured/jointed granite bedrock is common especially at Paya Terubong-Relau and Sg. Ara. These are also areas with identified fault zones.

The construction of the tunnel cause a deformation of the soils and rocks around the excavation area/portal area.

Potential impacts:

Risk of sudden collapses, subsidence and sinking that can damage both, the work under construction and existing nearby structures (condominiums, Kek Lock Si Temple, Air Itam dam and Bukit Bendera complex).

High risk of sudden collapse can happen in areas that intersect with the fault zones in Paya Terubong.

Condition/Activity:

Interaction with surface water and/or groundwater.

Seepage could develop in the open cut areas, especially in the fractured zone area.
Excavation of tunnels has a draining effect leading to a generalized drawdown of groundwater.

Potential impacts:

Water resources impoverishment, pollution risk, and affect workers safety.
Seepage might lead to rock stability failure. Shall not be allowed.

If not completely waterproofed may result in qualitative changes of the groundwater, changes in surface stability.

Statements as quoted above from the EIA report reflect the seriousness with which the geological and geotechnical concerns are professionally expressed by the two geology and geotechnical consultants in the EIA study team.

The main point I made is that the EIA team should then have done due diligence to carry out more detailed investigations to determine the risk or safety factors associated with tunneling, specific to the existing conditions of the proposed project sites. Or in Ng’s words: “under what circumstances they (ie the risks) can arise and what the probability is of them occurring”.

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Surely not conducting more detailed investigations, or not reporting if such investigations have been conducted, constitutes a serious shortcoming of the EIA report.

If the expert opinion by other geologists is that these concerns are unfounded and, quoting Ng, that “the EIA report itself has planted the seeds of suspicion and fear” then it brings to question if the EIA report is not only deficient but also misleading and whether it should be accepted on these grounds.

The other issues raised by Ng, questioning the amount of rock debris and quantity of explosives (which by the way was not mentioned by me in my talk, as can be verified from the online video of my talk) are the very questions that ought to be raised as omissions and vagueness in the EIA report.

It is incumbent on the EIA study team to estimate the amount of rock debris that would result from excavating 10.1km of twin horse-shoe shaped tunnels.

Our estimate is based on the cross section geometry of the tunnels as revealed in Figure 5.3.23 of the EIA report, reproduced here. It is not stated how many emergency cross passages will be constructed. The amount of rock debris to be transported away from the project site is obviously not trivial.

Cross-section view of PIL tunnel

While it may be usual for large-capacity lorries to be used for transporting quarry products, it has to be taken into consideration that the access roads identified for the transportation have limited capacity for large trucks. For example, the single access road (shown in the photo at the top) for transporting rock debris and construction wastes from the south portal of Tunnel 1, the north portal of Tunnel 2 and the viaduct connecting the two portals, identified in Figures 8.4 (b) and (c) in the EIA Report, is narrow, winding and with limited space for road widening.

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Ng suggested that “if there is any genuine concern over these issues, they can be raised in the form of written questions to the Department of Environment”. This is precisely what the talk was intended for, that the audience is told what is said and not said in the EIA report so that the public can raise their concerns in their feedback to the Department of Environment as allowed for in the Environmental Quality Act 1974 of Malaysia.

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Xiong Yee The Anchor Boy
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Xiong Yee The Anchor Boy

Next Up : break up of Umno, many deserted party so as not to be implicated by final 1MDB verdict. The breakaways to form new 3rd force and MCA MIC Gelakan to be alliance intolerant of umno-pas formation???

Zak
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Zak

Faction of PKR to join force with a certain faction of Umno to form a new malay party. Likely so Azmin and Rafizi are causing the split. Never know the permutations if you consider other factions from Bersstu and PAS. The malay community is certainly confused with so many mslay parties come PRU15.

Norman
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Norman

High number of cars (also on the rise) on the road is the real concern. If the number can be decreased, then no need for tunnels or highways. Meanwhile in Singapore, its Land Transport Authority (LTA) is looking to make car-lite modes of transport – like walking, cycling, and riding buses and trains – the preferred choices for commuters. It is seeking public feedback on how this should be achieved, from developing more road corridors with dedicated bus lanes and cycling paths, to having more direct travel options such as on-demand, dynamically routed bus services. https://www.straitstimes.com/singapore/transport/lta-seeks-public-feedback-on-promoting-walking-cycling-and-riding-among https://www.channelnewsasia.com/news/singapore/lta-launches-public-engagement-land-transport-master-plan-10735880 Singapore built 200km… Read more »

Norman
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Norman

Learn from Singapore that has just launched the public engagement for the next Land Transport Master Plan (#LTMP) 2040:

Learn more about #LTMP2040 and and how the Singapore public can shape the future land transport system at http://www.lta.gov.sg/ltmp2040

Kimmy
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Kimmy

Singapore offers good lessons to us in this aspect.

tunglang
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tunglang

This was a hill road of my choice for marathon training of stamina in the 1980s. I used to run up this hill road on morning Sundays and continued running circling the entire Air Itam Dam 4 times for a total of 13.5 km run. On Wednesday’s late afternoons, I trained running up this hill road but upon reaching the dam’s carpark continued with the more challenging steeper hill road on the left turn (near the toilet) which climbed another 2+ km the end of which one could enjoy the sight of 3 giant TM’s telecom towers. The reward was… Read more »

Norman
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Norman

Tunglang at your age to keep running you may need Ebene on your knees, Anlene for stronger bones, and Ensure for added energy and vitality. Extra expenses, not SST exempted.

Shriek
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Shriek

He is a school runner. Running away from sch.

tunglang
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tunglang

Drink a lot of Kopi-O (kau kau),
consume Sour Sop (for energy & cell building),
take TCM supplements (Yang elements for healthy life),
say no, no to Ying cold beers after a run (as opposed to Hash House Harriers),
meditate in the rainforest (Bunians are such great advisors),
listen to Calmradio.com New Age Zen Music,
eat more vege & less meat,
sleep 6 – 7 hours daily,
live / do your best – at work, at play for a more balance body-mind-spirit.
what else? Oh yes. Don’t shriek for health-goodness sake! God is not deaf!

Shriek
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Shriek

And not forget to call others dude kau beh kau bu add to ah gee and ah jo

Norman
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Norman

Also must avoid the illicit Mandalay Whiskey! Cheap but Deadly.

tunglang
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tunglang

I don’t touch alcoholic beverages except lite beer during CNY.
Chinese red wine (in black ceramic bottle) will knock me out in minutes!

Heng GS
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Heng GS

Tunglang had a lot of yesteryears Penang tales to tell, and should collaborate with Anil to seek wider readership via e-book publishings, so that future generations can access to the past thru Penang Digital Library.

Shriek
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Shriek

He is the Ah Pek our senior citizen and like grumbly old man

tunglang
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tunglang

I may look younger than you Shrieker!
Already some ladies asked me what’s my secret to staying younger + agile.
I am looking forward to being a senior citizen as I will enjoy a good discount for applying a Pg Rapid Emas (for senior citizens) @ Rm35.
Cheers Kopi-O kau kau kau!

tunglang
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tunglang

Missing hiker found alive says he followed a ‘princess’ into Mt Singai https://malaysia.yahoo.com/news/missing-hiker-found-alive-says-084432327.html KUCHING: A man, who went missing for six days while hiking at Mount Singai in Bau near here, told rescuers that he followed a ‘beautiful woman resembling a princess’ into the mountain. Stanley Kho, 22, also told rescuers that the ‘woman’ gave him flowers plucked from the forest before he proceeded with his journey. A Fire and Rescue Department spokesman, who was involved in the search and rescue (SAR) mission mounted for Kho, said the latter was mesmerised by the beauty of the ‘woman’ that he followed… Read more »

Heng GS
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Heng GS

Anil we missed the event as you put it as 22sep which is Saturday.
Your typo is costly should be 20Sep as more can turn up.
Be careful with date in future. Thanks.

Tokidon
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Tokidon

Korek tunnel use the soil the reclaim islands?

tunglang
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tunglang

Korek, korek, korek. Penangites pay the hefty price. But Chow don’t care!

Dire Straits Penang
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Dire Straits Penang

Hopefully it’s a tunnel of love and no disaster

https://youtu.be/gAirINwjaxE

Aaron Kong
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Aaron Kong

Now it’s ‘Brothers In Arms’ for Umno and PAS.
It’s ‘Money For Nothing’ after (allegedly) accepting RM90 donation.

Zak
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Zak

Our nation’s finance in dire straits due to huge debts.
PTPTN debtors please pay back loan.