Possible Clues:

• Sullied
• Far from pristine outbuilding on lake island
• New shirt dean spoilt
• Water I discarded is contaminated
• That's the water I got rid of is because it looked so dull
• The little lake with no shine on its surface that I got rid of
• The drain's badly stained
• Discoloured water I poured out
• Threads in fashion lost their lustre?
• Water I poured is discoloured