All fire fighting foams have to some degree or other an unacceptable impact on the environment when released in an uncontrolled or regulated manner. Roger A. Klein looks at the disposal, remediation and lifetime costs of fire fighting foam.

Class A or Class B formulations all have BOD/COD values that are high enough to be of considerable concern to environmental regulators if discharged into waterways or other bodies of water either as finished foam or as concentrate. One is caught, however, between an environmental Scylla and Charybdis, between a rock and a hard place: on the one hand rapid degradation is desirable with a BOD28 greater than 90% but this implies a relatively short half-life and a high BOD5 which increases acute oxygen stress; on the other hand a low BOD5 means extended >90% degradation times well in excess of 28 days. Moreover, some components may also be acutely toxic to biological systems. Fluorosurfactant foams (AFFF, FP, FFFP and their AR variants) give rise to extremely stable, environmentally persistent fluorinated degradation products. Fluorine-free (F3) foams, however, by their very nature, do not. This distinguishing difference has important practical environmental advantages.

Large-scale operational incidents can produce huge quantities of firewater runoff, running to tens of millions of litres. This runoff will be contaminated not only with foam used to fight the fire but also with a mixture of chemicals depending on the incident site. At the Allied Colloids fire near Bradford (UK) in 1992, millions of litres of runoff containing a toxic cocktail of some 400 chemicals had to be diverted through the storm water bypass at the local sewage works serving a very large urban population, in order to protect the treatment beds. The result was a significant river-kill in the Aire and Calder rivers for some 50 km downstream. In December 2005 the fire at Buncefield contaminated the drinking water aquifer for North London with fuel mixed with fire fighting foam, mainly because the tank bunds failed as a result of the fuel dissolving the seals between the bund walls and around service pipes. With the fire at the Kosan refinery in Hokkaido, Japan, in 2003, the advantages of using fluorine-free (F3) foam compared to an AFFF were clearly illustrated in the ability to discharge firewater runoff sooner without expensive remediation.  After recovering any oil, fire fighting water containing fluorine-free foam was held bunded for 30 days, before being given the OK by regulators for release into the ocean. However, AFFF-contaminated runoff in tanks and bunded areas was held for about three years before being treated at considerable expense.

Training sites can give rise to significant environmental contamination. Probably the two best-documented examples available are the former US Military fire training grounds investigated by Jennifer Field and her colleagues at Oregon State University (Schultz et al. (2004) Environ. Sci. Technol.38, 1828-1835), and the groundwater contamination resulting from ARFF training at Jersey Airport in the Channel Islands.

Schultz et al. (2004) clearly showed that continued use of training areas over many years had resulted in significant contamination of groundwater with breakdown products of both PFOS-based and fluorotelomer-based formulations, essentially fingerprinting foam usage. Additionally these results showed the extremely environmentally persistent nature of these fluorinated materials. Some groundwater samples still foamed 10-15 years after the sites were last used and the highest concentration of pollutant found was 14,600 microgram per litre 6:2 fluorotelomer sulphonate (6:2 FtS)(14.6 mg/l), an astonishingly high level for an environmental contaminant.

Information published by the States of Jersey in 2004 about the Jersey Airport Fire Service foam training ground contamination of the island's drinking water aquifer with PFOS provides an unusual insight into remediation costs even for a relatively small incident ('Jersey Airport: Fireground Remediation – Deed of Settlement', lodged ‘au Greffe’ on 19^th October 2004 by the Harbours and Airport Committee.

It is unusual to have financial estimates for remediation costs released into the public domain as this is normally considered commercially or politically sensitive, as was clear from a Channel News TV report at the time.

Section §4.7 of the Deed of Settlement listed four possible remediation strategies, whilst estimated budgeting needs at 1999-2000 prices. The options included:

(i) Removal of the entire Fire Training Ground to a depth of 30 metres and construction of a replacement Fire Training Ground – total estimated cost £30 million at 1999 prices;

(ii) Alternatively removal of contaminated stone to a depth of 10 metres rather than 30 metres, then as in (i) – total estimated cost £22 million at 1999 prices;

(iii) A four part scheme consisting of (a) lifting approximately 2 metres of contaminated soil, shale and rock, and placing this on an impermeable base with a covering of soil and grass, leaving it as a bund on the outside edge of the training ground; (b) insertion of a deep concrete wall to prevent groundwater running through the site; (c) placing a concrete cap on an impermeable base so that fire appliances could train using a new rig installed with containment of all burnt and unburnt fuel, as well as firewater runoff contaminated with foam and other residues; (d) installation of a new LPG or oil training rig. Estimated cost between £3.7 and £4.9 million (at 2000 prices).

(iv) Doing nothing at all – recognised as completely unacceptable for environmental, health and political reasons.

Apart from the long term remediation costs incurred by this incident, likely to ongoing and increasing, other costs included legal and analytical fees, the provision of bottled drinking water to members of the public affected, as well as political costs which are much more difficult to quantify.

Accidental discharges from fixed systems have also caused detectable environmental contamination. Examples include the discharge of 22,000 litres of 3M LightWater AFFF (containing FC-206 fluorosurfactant) plus 450,000 litres of water on June 8, 2000, at Toronto Pearson Airport, Canada, from an aircraft hanger sprinkler system; approximately 330-1650 kg of total PFOS-related PFCs were released. The runoff entered Spring Creek and then Etobicoke Creek ultimately polluting Lake Ontario. Subsequently in August 2005, a further 48,000 litres of AFFF entered Etobicoke Creek as a result of extinguishing the fire caused by Air France AF358 over-running the runway; however, on this occasion the AFFF used did not contain PFOS as it was a fluorotelomer-based AFFF.  Ten years after the 2000 incident PFOS levels downstream were still elevated especially in sediments and in fish liver (Awad et al. (2011)  Env. Sci. Technol. 45, 8081-8089), indicating that release of PFCs to the environment can have long-term impact.

More recently, in January 2013, a similar incident occurred in Cairns, Queensland. A fixed loading bay deluge system was triggered by ants in a switch box, resulting in 31,000 litres of foam being discharged into Trinity Inlet, Cairns, leading to potential environmental pollution by PFCs of one of the most ecologically sensitive habitats in the world, the Great Barrier Reef Marine Reserve. The release, which happened outside normal working hours, went unchecked because the automatic discharge warning system relied on communications systems that had been compromised by severe flooding in North Queensland (Murphy’s Law for worst case scenarios – what can go wrong, will go wrong!). The direct and indirect costs of this incident are not yet clear as investigations are still be carried out, but will certainly be considerable involving amongst others analytical, consultancy and legal costs.