Some 99.8% of California companies covered by the WCI met the market’s first two-year compliance period, a spokesman for the state’s regulators ARB said Tuesday.

Around 290.2 million units were turned in compared to California’s 290.7 million tonne cap, leaving around 500,000 tonnes unaccounted for.

The spokesman didn’t say whether the shortfall was from one or more installations.

Any entities not in compliance will have until mid-December to hand in four times the required allowances to avoid breaching the law, an oversight that could carry with it a bill of up to $20 million based on current market prices.

The 2013-2014 compliance period for California and Quebec’s linked markets ended on Nov. 1, obliging industrial plants and power stations to surrender allowances covering all their 2014 emissions and 70% of their 2013 emissions. They were required to hand in permits covering the first 30% a year ago.

Analysts predict the WCI will have a surplus of 30-33 million tonnes for the period. The compliance data is due to be published on Wednesday.

By Mike Szabo and Ben Garside – news@carbon-pulse.com