The amount of signatures and time requirement are up in the area, depending on how many registered voters are in the District. In 2018, there were 9,632. If the total is over 10000, petitioners will have 120 days to collect 20% of those. If it is under 10000, than they have 90 days to collect 25 percent.
Update: The recall is still ongoing, though there is now also a move to censure Nosrati.