Abstract: A filter has a sealing portion and a filtering portion coupled to the sealing portion. The sealing portion is configured to form a seal with an inner surface of a conduit to inhibit the liquid from passing through the conduit outside of the filter assembly. Further, the sealing portion has a passage therethrough to permit the liquid to pass through the sealing portion into the filtering portion. The filter also has any combination of one or more of the following characteristics: (i) the filter is installable flush with or entirely below the inlet of the conduit, (ii) the filter has an oil-solidifying substance that solidifies oils, such as hydrocarbons, passing through the filter, and (iii) the filter has an oleophobic and hydrophilic substance that inhibits oils from passing through the filtering portion.