MANILA, Philippines?It all started in the first week of October with a call from a former student now working with the Makati City Hall. He was asking if the National Institute of Geological Sciences (NIGS) could help locate the source of the fuel leak in West Tower condominium in Barangay (village) Bangkal, Makati.

A memorandum from UP President Emerlinda Roman followed, directing me to help Makati upon the request of Mayor Junjun Binay.

It had been almost four months since petroleum products started seeping into the basement of West Tower, and up to that time, the source of the leak was unknown. All residents of the condominium had been forced out of their homes since late July when petrochemical fumes were accumulating in the basement and seeping into other parts of the building, making it unsafe, according to the Makati City Engineer?s office.

A-Team

We had to form a team immediately. We were able to get the assistance of Florencio Ballesteros Jr., professor of environmental engineering (PhD at New Jersey Institute of Technology) at UP Diliman; Edmundo Vargas, hydrogeologist (MSc candidate at NIGS, UP Diliman); Davee Drake Medina, hydrogeologist (MSc from NIGS, UP Diliman); Benjamin de Jesus (PhD in biology, UP Diliman); Louernie Papa de Sales, professor of environmental engineering, UP Diliman; and Engineer Renato Abundo, who was a Petron construction manager and a lead person in environmental remediation. I have a master?s and PhD in geotechnical engineering and geosciences from the University of Illinois.

This team is the A-Team and the reason the leak in the pipeline was found.

Clear, present danger

Abundo pointed out immediately that the four-level basement in West Tower could be accumulating hydrocarbon vapors because of the leak. This posed a grave danger because the vapors could explode as the basement was effectively an enclosed cavern.

While there were a few ventilation fans, there was an extremely strong smell of hydrocarbons in the basement. We needed quantitative detectors that could determine lower explosive limits (LEL). At a cost of P90,000 each, we were able to acquire two explosimeters (RAE brand) that could measure not only LEL but also carbon monoxide, oxygen and hydrogen sulfide levels.

With these instruments, we explored the basement and found a 6-percent maximum LEL in the lowest level?not enough to cause an explosion, but not yet ventilated thoroughly.

Clearly, the hydrocarbon vapors had to be emptied from the basement and it was these vapors that caused the Makati government to declare the West Tower building unsafe. I got in touch with ventilation experts from mining companies and the Mines and Geosciences Bureau who suggested contacts for acquiring explosion-proof ventilation systems.

Potential sources

With the potential explosion of the basement ruled out, we could then proceed with hunting for the source of the leak and designing a system of purging the tainted groundwater entering the basement.

Why did it take so long to discover the source of the leak? Aside from the pipeline, several potential sources were considered:

The car repair shops nearby that could leak used oil

Several gasoline stations

Fuel stored within West Tower for its generators

World War II-era buried fuel tank beside West Tower detected by ground-penetrating radar

The pipeline which is closest to the building

Scientific method

The scientific method dictates the ruling out of competing hypotheses by testing, which we followed religiously. When we started working in the second week of October, what we knew were the following facts:

Groundwater mixed with hydrocarbons was flowing into the basement. This polluted water was being pumped out and treated on site and fuel was being recovered, about 10-20 barrels per day! Approximately more than three large tankers of fuel had been recovered by mid-October. The fuel was sometimes gasoline, sometimes diesel and sometimes kerosene. (This turned out to be very significant.)

The pipeline in front of West Tower (about 40 meters) was excavated and no leaks were found.

Studies on pipeline integrity (pig and magnetic flux) contracted by the Lopez-owned First Philippine Industrial Corp. (FPIC) suggested that there was no leak in the pipeline. These certified studies made FPIC adamant that the leak was not coming from its pipeline.

Ruled out

Upon further analysis and with the passage of time, the large volumes of pure fuel collected effectively ruled out the car repair shops, the West Tower-stored fuel and even the gasoline stations as source of the leak. That left the ?buried metal tank? and the FPIC pipeline as the sources of the leak.

Several factors suggested that the pipeline was the source. The proximity of the pipeline and the different types of petroleum products recovered in batches from the basement: sometimes gasoline, sometimes aviation fuel, sometimes diesel, which mimic the designed batch flow procedure in the pipeline.

The different types of fuel found in the condominium cannot be explained by a single underground storage tank (aside from the huge volumes discharged). The buried fuel tank had to be ruled out.

Ground-penetrating radar

Upon reviewing the ground-penetrating-radar (GPR) data, we realized that two companies had indeed conducted the GPR, but only one claimed the existence of the buried metal object.

The company, which in fact had 10 more passes by GPR in the same area, did not detect anything. To clear up this confusion, we decided to drill three holes in the purported location of the buried metal object?all we found was adobe. No fuel tank, no buried metal object. This meant that the pipeline was the source, but where in the pipeline?

German pig vs PH worm

FPIC was confident that its pipeline had no leak because aside from excavating 40 meters of the pipeline right in front of West Tower plus many other test pits in the area, it had just spent more than $2 million on foreign consultants who used sophisticated magnetic flux and ultrasound tests on the entire length of the pipeline in July 2010. [The pipeline runs from Batangas to the fuel depots in Pandacan, Manila.]

This ?intelligent pig? consists of an object sent through the pipeline detecting metal corrosion by means of magnetic flux changes. Based on this expensive pig tests, the foreign consultants certified that the pipeline had no leak?yet here we were, local scientists with no choice but to attribute the leak to the pipeline. What we needed was concrete evidence.

To get this evidence, we decided to drill exploratory wells, in all more than 40 of them, a few meters down gradient of the pipeline. These wells were no more than 10 meters deep, but we used pipes with slits into which petroleum vapors could seep.

The idea was very simple?if the pipeline had leaks, the petroleum products would seep into the soil and bedrock and vapors would diffuse. If these vapors could get collected inside our exploratory wells, they will be detected by using explosimeters. Thus, we called our exploratory wells ?worms? and the battle between the pig and the worm began.

Our first wells north of West Tower had negative results for petroleum vapors although we had one hole that had elevated LEL readings. When we started drilling wells south of the building, we immediately obtained elevated petroleum readings. In one such hole we not only recorded 100-percent LEL readings but also had pure gasoline coming out of our hole along with drilling water.

Leak found

Eureka! The leak was found! FPIC had no choice but to excavate this area. On October 28 at around 5 a.m., FPIC was excavating the concrete cover of the pipeline near the Magallanes flyover when a continuous stream of pure fuel was observed and videotaped flowing out.

Interestingly, an FPIC engineer not wanting to have the leak seen turned off the lights, but our camera still documented the substantial flow. The actual location of the leak (five mongo-sized holes) would still take almost another week to locate.

Sand layer

Now that the pipe has been repaired, it is quite intriguing to observe that fuel continues to flow into the basement of West Tower at 15 to 20 barrels per day! Does this mean that there are other leaks?

I think not, but fuel continues to flow because our drilling revealed a pervasive sand layer beneath the adobe.

This sand layer is very permeable and acted like a sponge to absorb the leaked petroleum from the pipeline.

The sand layer contains probably thousands of barrels of petroleum products and is the reason fuel continues to flow into the basement.

Deepest structure

As it turns out, the basement is the deepest structure in the area. This cavern acted like a cistern for the leaked fuel. Until the fuel contained in the pores of the soil and rock outside the condominium is pumped out and cleaned, fuel will continue to seep in and render the building uninhabitable.

The most immediate remediation that needs to be done now is to divert the fuel flow outside of West Tower by constructing large-volume capture or intercept wells that will divert groundwater flow and prevent collection of fuel in the basement.

Since the water table close to West Tower is quite shallow (2-3 meters deep), trenches may also be employed to capture the fuel flowing into the basement.

What caused the leak?

With the available data, one could point to a causal relationship between the location of the leak and the Magallanes flyover whose vibrations due to numerous trucks using it might have caused metal fatigue. We have not (yet) seen leaks in the pipeline unrelated to the flyover. This is why even after fixing the leak, a long-term approach would be to construct a bypass to avoid the stresses coming from the flyover.

Lessons learned

Perhaps one of the most important lessons we can learn from this catastrophe is to correct our tendency for overdependence on foreign consultants even in the face of glaring contrary evidence.

FPIC was probably complacent because its German pig consultants and its GPR consultants all suggested that its pipeline wasn?t leaking. On the contrary, the pattern and the kind of fuel leaking into the basement of West Tower clearly indicated the pipeline as the origin!

FPIC lost a lot of credibility (and will pay damages) because its pipeline was leaking when it was denying the fact all along.

Another important lesson is immediate transparency because a leak of this magnitude cannot be hidden forever. Many Bangkal residents and even some West Tower people I talked to were willing to be more forgiving if the pipeline leak was admitted by FPIC early on and help was extended to them as soon as possible.

I have since seen FPIC personnel sincerely trying to make things right, but it will take time to regain lost credibility.

Accountability

FPIC has publicly apologized for the leak and promised to pay damages and cleanup costs. The problem is that the magnitude of the cost and cleanup will be staggering. There are still thousands of barrels of petroleum products contaminating the soil and groundwater in the area.

These will need to be pumped out and the soil cleared of all petroleum traces. The extent of the contamination plume can only be delineated by drilling dozens of monitoring wells. The cleanup costs will easily run into billions of pesos if this is done properly. We hope and pray that FPIC has enough insurance and resources to cover all these costs.

Eerie silence

While working feverishly in Bangkal (even with much-delayed payment), I was bothered by the eerie silence and absence of the customers of the FPIC pipeline that carried their petroleum products?Shell and Chevron.

Understandably, they can always point to FPIC as the main culprit for the leak, but it is now undeniable that their products are the ones polluting the soil and groundwater in Bangkal. Senator Juan Miguel Zubiri, at the Senate hearing on November 16, quizzed Chevron and Shell executives on their actual losses during the past months when the leak was happening.

Clearly, hundreds of thousands, maybe millions, of liters of petroleum products leaked, but why were the owners silent? Republic Act No. 6969 (Hazardous Wastes Act) states that custody for hazardous wastes belongs to its owner from cradle to grave?but are petroleum products in fact hazardous waste when it is leaked into the ground?

Responsibility

In other countries, responsibility for pipeline leaks lies not only with the pipeline contractors but also with the product owners. The most famous case is the British Petroleum (BP) in the Gulf of Mexico; BP was held accountable. Even if it wasn?t its drilling rig that exploded, which caused the oil spill, it owned the oil.

In the Philippines, the best example is the sinking of a ship in a storm carrying Petron petroleum. It was Petron, not the ship owner, that paid for cleanup costs.

Ultimately, this is a matter that will be resolved in the courts, but Bangkal and West Tower residents need help in cleaning up the environment. An appeal can be justly made in this case for Chevron and Shell, being the product owners, to help substantially and visibly in cleaning up their products that have polluted the environment.

With the issuance of the writ of kalikasan by the Supreme Court on November 19, the pipeline will remain closed until it is shown to be safe. Since a leak has been discovered in Bangkal, how does one prove that it is leak-free in the rest of its 117-kilometer length? Interesting question but that is another story.

(Carlo Arcilla is the director of the National Institute of Geological Sciences, College of Science, University of the Philippines Diliman.)