Finally!
I couldn't find it in Wal-Mart or Wal-Mart Supercenter.
Went to Lowe's in Chino Hills, was told they had it in stock. But when I went to the back, they guys told me someone bought it all. Boo! Since I have the part #, I asked him to check if there are any stores that still had them. He told me:
Upland, Riverside, Puente Hills, and may be Rancho Cucamonga. Drove to Puente Hills and asked. Once again, they said they don't carry it.
Give the guy the part #, and the computer show 20 in stock! So we started looking for it. And I finally found it! It's i the section where all the 2' x 4' plywoods are. And the pile was covered with a couple 2' x 4' plywoods on top. Any how, now to the drawing board on what the sump will be like! Thank you all for the help!