During the heyday of the coalmining industry in the 1940's, nearly one-fifth of Sanhsia's population was employed in over 20 active mine shafts.
然而市面上「文山包種」、「凍頂烏龍」的名氣卻響得多，價錢也高，「三峽龍井」一直難望項背。這些貨棄於地或上貨賣不到好價的現象，實值得三峽居民三思。