From "Elevated airborne beta levels in Pacific/West Coast US States and trends in hypothyroidism among newborns after the Fukushima nuclear meltdown", by Joseph J. Mangano, Janette D. Sherman, page 3 (link):
A national study conducted by the National Geological Survey examined concentrations of wet depositions of fission-produced isotopes in soil at sites across the US, for several radioisotopes, between March 15 and April 5, 2011. Results showed that for I-131, the highest depositions, in becquerels per cubic meter, occurred in northwest Oregon (5100), central California (1610), northern Colorado (833), coastal California (211), and western Washington (60.4). No other station recorded concentrations above 13. Similar results were observed for Cesium-134 and Cesium-137 . All the cited locations are on or near the Pacific coast, with the exception of Colorado, in the western US.
Cubic meter??? That would be indeed catastrophic.
However, from "Wet Deposition of Fission-Product Isotopes to North America from the Fukushima Dai-ichi Incident, March 2011" by USGS, as cited by the authors (link):
Variable amounts of 131I, 134Cs, or 137Cs were measured at approximately 21% of sampled NADP sites distributed widely across the contiguous United States and Alaska. Calculated 1- to 2-week individual radionuclide deposition fluxes ranged from 0.47 to 5100 Becquerels per square meter during the sampling period.
It was "square meter".
Open file report by USGS: http://pubs.usgs.gov/of/2011/1277/
Table 2 on pages 17 and 18 of the USGS report shows I-131, Cs-134, Cs-137 deposition. Many places have only Cs-137 detected, some places with I-131 and Cs-137, some with I-131 and Cs-134. For locations that have both Cs-134 and Cs-137, the ratio is mostly not in line with those of Fukushima-origin (Cs-134:Cs-137=1:1 to =1:1.2).
(Click to enlarge.)
1,090 picocurie is 40.33 becquerels. 40.33 becquerels/liter was calculated into 5,100 becquerels/square meter, with the conversion factor of about 126.