Reducing run-off

05 Jan 2014
Portland’s pervious asphalt saved the port over $250,000

Portland’s pervious asphalt saved the port over $250,000

Reducing the environmental import of port development can actually save money. Dave MacIntyre reports

In an age where reducing carbon footprint is becoming ever-more important, some ports are opting to embrace Low Impact Development (LID) within their core planning values.

LID refers to port development that least influences the original state of the land and best minimises the impact of that development on natural habitats, landscape features and drainage paths.

The most well-known area for such measures is water run-off, where sustainable urban drainage solutions (SUDS) allow natural permeation, instead of laying down huge areas of non-permeable tarmac.

That is part of the approach being followed by the US port of Portland. At its Terminal 6 facility it now has 35 acres of porous asphalt and bioswales to absorb rainwater and runoff from the adjacent non-porous blacktop.

Porous blacktop allows rainwater to penetrate the surface and recharge the ground water in a more natural fashion than a normal tarmac surface.

 

Savings pot

Community affairs manager Christine White says that there were also cost benefits for the port in taking such an approach.

“While costs for porous blacktop are greater due to the need for a large layer of aggregate stone to absorb water under the asphalt, there are savings from reduced permitting requirements and the fact that no stormwater system is necessary. Porous blacktop has the added benefit in warm weather of allowing stormwater to cool before entering the river.

“In the end, we realised about $255,000 in savings by using porous blacktop, so this was a win for the environment and for our bottom line.”

Portland has adopted a LID approach in other areas too. At its Rivergate Industrial Park in north Portland, the port built an undercrossing beneath a busy stretch of road to help western painted turtles and other wildlife species move between wetland areas without having to compete with car, truck and train traffic.

This project was the winner of the 2008 American Association of Port Authorities’ Award for Environmental Enhancement.

Portland is also aiming to reduce its greenhouse gas production by reducing the amount of time engines spend idling. At marine Terminal 6, cargo-carrying trucks waiting to be processed could line up 20-deep. A multimillion dollar optical card reader now reduces engine idling by processing up to three trucks per minute.

This speedier entry into T6 not only reduces the emission of greenhouse gases, but also reduces the amount of all air emissions, including particulate matter and hazardous air pollutants.

 

Alternative thinking

Also in the Pacific North West, the port of Bellingham is doing its bit to embrace LID philosophies. It sees LID technology as an alternative comprehensive approach to stormwater management that works with nature to manage stormwater as close to its source as possible using strategies such as environmentally sensitive rain gardens and pervious pavements.

Bellingham has an Environmental Compliance and Assessment Program (ECAP) designed to minimise the environmental impacts of tenant activities and maintain regulatory compliance through education and compliance assessment.

Mike Hogan, Bellingham’s environmental analyst, says the port is located adjacent to Puget Sound, the nation’s second-largest marine estuary, which has suffered from rapid population growth and urbanisation.

“When rain flows along streets, parking lots, and rooftops it soaks up toxic metals, oil and grease, pesticides and herbicides, faeces, and other contaminants before discharging into the waters of the Puget Sound. Rather than seeping into the ground, this runoff quickly flows or floods downstream from developed land during the rainy season. Today, polluted stormwater runoff from paved areas is the biggest threat to water quality in the Puget Sound.

“Stormwater management techniques have traditionally used pipes and drains to remove runoff quickly. LID is an alternative strategy that seeks to mimic natural processes to manage rainfall at the source and protect water quality.

“The use of LID (raingardens, bioswales, pervious pavement, etc.) has increasingly grown in importance and use in Washington State. Bellingham strives to achieve sustainability in its practices and seeks opportunities to integrate LID stormwater management techniques whenever practical and appropriate.”

To that end, the port has installed rain gardens at its transportation terminals and has sponsored workshops to promote LID strategies and responsible stormwater management.

 

Special fit

However, Mr Hogan adds that while LID is an important tool for stormwater management, it is not a one-size-fits-all solution. “Many port facilities are located on waterfront land which is not conducive to LID strategies due to low permeability soils and a high groundwater table.

“Many waterfront properties located on Bellingham Bay contain soil or groundwater contamination as the result of historic industrial activities. The port is currently redeveloping 237 acres of waterfront property in Bellingham’s downtown waterfront which includes six state-listed contaminated sites. Stormwater infiltration could introduce additional pollutant loads to groundwater and nearby surface waters.”

To evaluate the potential for using LID approaches on contaminated areas of Bellingham’s central waterfront, the port is collaborating with designers, engineers, regulators, developers and other key stakeholders to discuss LID strategies.

On the other side of the world in the Middle East, the Port of Salalah is reacting to the fact that a major environmental issue facing the Dhofar region is the loss of native trees, which impacts on local biological resources. One resource at risk is the valuable frankincense tree, which requires urgent conservation efforts.

 

Planting plan

The Port of Salalah’s response is a planting drive, underpinned by turning industrial oil drums into pots for native trees. A total of 50 oil drums were turned into pots for frankincense saplings. Forty are being sent to local schools and clinics, as a reflection of the port’s LID philosophies.

This was marked by an Oman Environment Day, building on a previous event where employees celebrated World Earth Day by planting saplings in nearby conservation parks, approximately 30 minutes into the mountainous region surrounding the port.

Braik Khadim Frijoon, environment supervisor HSSE at Salalah, says the recycled oil drums carry an eco-conscious message. Another innovation to be launched soon will involve the recycling of used tyres and turning them into 'protective edges' around containers.

“From the beginning of its operations the port has engaged the community with clean beach drives at several beaches in and around Dhofar. Since the health of the ocean is very important to the nature of port operations, this year we are reaching people at their workplace and homes with these trees as an example to take care of the environment.”

As the port in Oman actively espouses its green and LID message, Salalah expects other ports in the region to see these activities as a benchmark for success. Mr Al Mashani says the port management believes it is extremely close to convincing the Omani government to invest in its proposal to convert 70 RTG cranes from diesel to electrical, which is the final major leg of the SWITCH (see box) aims.

“Ports’ operations … [are] perceived as an industry with a large energy footprint, but, we need to continue educating our community about both sides of impacts, good and bad.

“Sometimes due to the focus on other priorities the environment gets pushed down to the end of the list but that is visibly changing in that the value of taking care of our environmental costs and impacts need to be better managed, recorded and reported.”

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