Please follow http://nwis.waterdata.usgs.gov/ca/nwis/gwlevels?multiple_site_no=340829117284301%2C340829117284302&group_key=NONE&sitefile_output_format=html_table&column_name=agency_cd&column_name=site_no&column_name=station_nm&format=html_table&date_format=YYYY-MM-DD&rdb_compression=file&list_of_search_criteria=multiple_site_no.