The pure substance of water mixes with the waste. The waste does not dissolve into the water, therefore it is a mixture.
Explanation:
Hybridization of O in 
So, water molecule has four hybrid orbitals.
Two hybrid orbitals form 2 sigma bond with two H atoms.
Remaining two hybrid orbitals are occupied by two lone pairs.
Because of lone pair-lone pair repulsion, shape of
becomes bent.
Water molecule is polar because of difference in eletronegativities of O and H.
O is more electronegative as comapared to hydrogen. So bonding electrons get attracted towards O atom which results in the development of partial negative charge on O atom and partial positive charge on H atoms.
Because of development of partial negative and partial positive charge, water molecule becomes polar.
Heating a substance will make the molecules move faster. It creates thermal energy