[M T]

I don't buy the construction theory.  Construction expanded on June 5 after the increases started. 
Edit: I thought construction was limited until June 5.  It appears it was permitted as of May 18,  with safety protocols. The safety protocols include detection of symptoms prior to the work day.  So construction sites may be detecting cases rather than spreading them. Considering pre-symptomatic infections, it may be doing both.

Construction is one of the areas . where COVID is spreading.  This June 12 news item lists more than 30 cases at construction sites.
SFGate reports "Since Memorial Day, 89 work sites in the county have reported at least one COVID-19 case. More than half of all work-site outbreaks are in the construction sector, and the largest outbreaks have occurred in food processing centers."
(With the possible exception of LTCF workers, cases are listed where they live, even if in a different county.)

The bottom of the daily % positive curve for  SCC happened May 24-29, and maybe was climbing a bit that week (the curve is too chaotic to be sure).
June 2 to June 9 was almost always higher than the highest of the previous week.
There was an anomalous low on June 13.
Jun 14 to 19 was at or above the levels of the week before.
(After that is still being changed daily, but currently Jun 20 is higher than any other date at 3.26%.  For comparison, FL reports 7.7%, Los Angeles is around 12%.)

I still believe this is sparked by the demonstrations and perhaps fueled by the subsequent openings, and some people's lack of following the protocols.

I sure wish attachments worked on this board.

(SCC has had a number of pop-up testing sites over at least the last month.  The state mandate is the capacity to test 2850 tests/day (for 1.9M).  Santa Clara county actual testing is above that number, per the state.  On the SCC map, I counted 43 sites that offered testing in the county.)

[M T]

I don't buy the construction theory.  Construction expanded on June 5 after the increases started. 
Edit: I thought construction was limited until June 5.  It appears it was permitted as of May 18,  with safety protocols. The safety protocols include detection of symptoms prior to the work day.  So construction sites may be detecting cases rather than spreading them. Considering pre-symptomatic infections, it may be doing both.

Construction is one of the areas . where COVID is spreading.  This June 12 news item lists more than 30 cases at construction sites.
SFGate reports "Since Memorial Day, 89 work sites in the county have reported at least one COVID-19 case. More than half of all work-site outbreaks are in the construction sector, and the largest outbreaks have occurred in food processing centers."
(With the possible exception of LTCF workers, cases are listed where they live, even if in a different county.)

The bottom of the daily % positive curve for  SCC happened May 24-29, and maybe was climbing a bit that week (the curve is too chaotic to be sure).
June 2 to June 9 was almost always higher than the highest of the previous week.
There was an anomalous low on June 13.
Jun 14 to 19 was at or above the levels of the week before.
(After that is still being changed daily, but currently Jun 20 is higher than any other date at 3.26%.  For comparison, FL reports 7.7%, Los Angeles is around 12%.)

I still believe this is sparked by the demonstrations and perhaps fueled by the subsequent openings, and some people's lack of following the protocols.

I sure wish attachments worked on this board.

(SCC has had a number of pop-up testing sites over at least the last month.  The state mandate is the capacity to test 2850 tests/day (for 1.9M).  Santa Clara county actual testing is above that number, per the state.  On the SCC map, I counted 43 sites that offered testing in the county.)