Provincial authorities are warning that one of Hamilton’s favourite recreational areas, and other parts of the Welland River, have been contaminated with a highly toxic chemical used in aviation fire suppression. The newly-released Guide to Eating Ontario Sport Fish shows that a globally-restricted flame retardant has been found in five popular game fish at the Binbrook Reservoir (also known as Lake Niapenco).

Perfluorooctanesulfonic acid (PFOS) was also found upstream of the lake in a Welland River tributary that flows out of Hamilton’s airport. The Ministry of the Environment’s biennial guidebook covering over 1900 sites is reporting PFOS-contamination from only two other sites in the province.

“Currently, there are four locations where concentrations have resulted in consumption restrictions,” explains the guidebook. “Consumption restrictions for PFOS begin at 0.080 parts per million with complete restriction advised for levels above 0.160 parts per million for the sensitive population and 0.640 parts per million for the general population.”

Of the six reported species at the Binbrook conservation area, PFOS was found in five – largemouth bass, smallmouth bass, channel catfish, carp and black crappie. For the first four, the Ministry says children under 15 and women of child-bearing age (“sensitive populations”) should eat zero meals per month and men should eat no more than two meals, and then only of smaller fish sizes tested.

Average meal sizes are defined as 8 ounces (227 grams) for an average adult. For the smaller black crappie species, contamination restricts consumption for everyone to no more than four meals per month.

The previous guidebook (2009-2010) endorsed up to eight carp meals a month for men and four for sensitive populations from the reservoir. Its restrictions were based primarily on agricultural pesticides and mercury, but no species at the lake reached the current levels of contamination.

The restrictions on carp at Binbrook are now virtually identical to those in force for Hamilton Harbour. The guidebook notes that “86.3 percent of all consumption restrictions on sport fish from inland locations are a result of mercury” and that very few of these sites “have been exposed to discharges of pesticides and other organic compounds which cause the majority of consumption restrictions on Great Lakes fish.”

The website of the Niagara Peninsula Conservation Authority describes the Binbrook conservation area as a “hot spot for fishing” that “plays host to annual fishing derbies” as well as providing swimming, picnic facilities and a “children’s spray pad”.

The volunteer Glanbrook Conservation Committee has been working for more than two decades to protect and enhance the recreational area. Its stated goal “for Lake Niapenco fisheries resources is to provide a healthy self-sustaining fishery with enhanced sport fishing opportunities.”

The popular 430-acre lake covers close to half the conservation area, and is part of the Welland River watershed, as is the upstream tributary from the airport that was tested where it crosses Upper James Street. In the latter site, PFOS is the only chemical contaminate in the one reported species that was tested.

The tributary site is not reported in earlier guidebooks so its testing this time suggests an attempt to determine the cause of the contamination downstream. A potential source of the flame retardant is a fire suppression training site at the city-owned airport that is managed by Tradeport International.

PFOS is restricted globally under the Stockholm Convention on Persistent Organic Pollutants. Its main producer, 3M, ended production a decade ago, and China is now the only global source.

Last fall, city council approved the urbanization of about 2500 acres of farmland for industrial uses and future airport expansion. The aerotropolis decision has been appealed to the Ontario Municipal Board.