This picture shows to me that the water is seeping in via a breakdown of the mortar immediately below the top of the pit light and also potentially other levels as well. Its a classic picture of the old pit when water invades everywhere and rusting all and sundry. I take it the pipe on the floor is the pressure regulator for both pipe rams or even the main oil line? Although the flex pipe on the wall looks like that too. Either way you will not fix this until they dig up the mulch area and lay down drainage to disperse the water.