Reduce precision of geojson feature geometry?

[dblodgett-usgs]

Precision of geojson is kind of crazy high.

e.g. https://labs.waterdata.usgs.gov/api/nldi/linked-data/nwissite/USGS-09372400/navigate/UM?f=json

-109.470320106 is five decimal digits is probably enough.

[EthanGrahn]

Taking a look at the PostGIS documentation, it doesn't seem we can set the precision at a database level. However, we have lines like this in the service code that we could adjust the precision of the output. (currently set to 9)