Some days, when we step outside our front door, we are greeted by the smell of the Crofton Mill. This paper and pulp mill (on Vancouver Island) is directly across the water from Vesuvius (on Salt Spring Island), and if the wind blows from the west, the smell of the mill blows toward our house. It is always a good reminder of how the wind ensures that the “non-local” is very much part of the “local,” just as when the smoke from forest fires elsewhere in BC makes for hazy skies over Salt Spring.
The characteristic pulp mill smell comes from sulfur compounds used in the pulp making process, which are collectively referred to as “total reduced sulfur” (TRS). The Pennsylvania Department of Environmental Protection provides a helpful explanation of the smells released in the pulp and paper industry:
Kraft pulping is the most commonly used paper pulping process in the United States. Wood chips are cooked in a digester under pressure in a solution of sodium sulfide and sodium hydroxide known as white cooking liquor to separate the lignin and cellulose. The cellulose (pulp) is then filtered, washed, bleached, pressed, and dried into paper. The sodium sulfide in the white cooking liquor is the source of the sulfur in the TRS compounds. Although hydrogen sulfide is generally the main TRS compound emitted from kraft pulping, several other compounds are formed during digestion as the sodium sulfide reacts with the lignin in the wood and with process gases. (1)
The Crofton Mill has, in recent years, run two paper machines and two kraft pulp lines (2). The mill, which was owned by the Catalyst Paper Corporation but purchased by Paper Excellence in March 2019 (3), reported on its TRS and other emissions (including greenhouse gases) in a Corporate Social Responsibility Report in 2016. The report lists TRS emissions in kilograms per day: from 214 kg/day in 2012, down to 170 kg/day in 2014, back up to 253 kg/day in 2015, and 225 kg/day in 2016 (4). For 2013, the Crofton Mill was listed as the no. 3 air polluter in BC, releasing a total of 5,802 tonnes of major air pollutants (5).
Catalyst Paper further explains:
British Columbia’s ‘A’ level ambient odour objective is two parts per billion average or less over a 24-hour day. Percentage compliance with this objective is a measure of the percentage of days in the year during which the daily average was at or below two parts per billion. (6)
The Crofton mill complied with this odour objective (which is a TRS emissions objective) 87% of the time in 2016, which was higher than the 80% from 2012 but a significant drop from the 93% compliance in 2015 (4). To translate: 13% non-compliance over a year (in 2016) meant 47 days of TRS emissions above the ‘A’ level ambient odour objective. I am guessing that the days we stepped outside and went, “Pffooey, it’s sure pulpmilly today!” were among those 47 days.
(1) Pennsylvania Department of Environmental Protection, Odors from Paper Mills (2018), http://www.depgreenport.state.pa.us/elibrary/PDFProvider.ashx?action=PDFStream&docID=4896&chksum=&revision=0&docName=ODORS+FROM+PAPER+MILLS.PDF+&nativeExt=pdf&PromptToSave=False&Size=172928&ViewerMode=2&overlay=0
(2) Catalyst Paper Corporation, Crofton Mill Fact Sheet (2017), https://www.catalystpaper.com/sites/default/files/user_uploads/crofton_mill_factsheet_aug2017_final.pdf
(3) Robert Barron, “Paper Excellence Finalizes Deal to Acquire Crofton’s Catalyst Paper,” Chemainus Valley Courier (March 18, 2019), https://www.chemainusvalleycourier.ca/home/paper-excellence-finalizes-deal-to-acquire-croftons-catalyst-paper/
(4) Catalyst Paper Corporation, Enduring Values, Constant Change (2016), 50, https://www.catalystpaper.com/sites/default/files/node_uploads/ir_reports/catalyst_csr_2016_spreads_lores.pdf
(5) Larry Pynn and Chad Skelton, “The Top 10 Air Polluters in B.C.,” Vancouver Sun (February 21, 2015), http://www.vancouversun.com/health/polluters/10831163/story.html
(6) Catalyst Paper Corporation, Glossary, https://www.catalystpaper.com/page/glossary