ʻO ka polymer concrete sump nā pūnāwai i uhi ʻia me nā poloka i ka wā e kanu ai i nā paipu ma lalo o ka lepo a i ʻole ka huli ʻana. He kūpono no ka nānā ʻana i ka pipeline maʻamau a me ka dredging. ʻO ka puna wai kaʻa resin kahi mea nui o ka ʻōnaehana wai. ʻAʻole wale ia e hana i ka dredging o ka ʻōnaehana hoʻoheheʻe, hōʻiliʻili i ka ʻōpala, a pale i ka hana maʻamau o ka ʻōnaehana wai, akā hiki ke hoʻohana ʻia ma ke ʻano he mākaʻikaʻi maikaʻi e pāʻani i kahi kuleana nui i ka mālama ʻana i ka ʻōnaehana wai. Loaʻa ka maikaʻi o ka hōʻiliʻili wai i nā hiʻohiʻona o ka nui kikoʻī, ke kaumaha māmā a me ka ikaika kiʻekiʻe, e hoʻopōkole loa i ka manawa hoʻokomo a he ʻāpana koʻikoʻi o ka ʻōnaehana wai i ke kūkulu ʻana i ka papahana.