In the Southern Hemisphere, where the June solstice is known as the shortest day of the year, it marks the first day of astronomical winter, but the middle of winter in meteorological terms.
Backfill refers to products or materials used to fill excavations. The most common form is composed of a mixture of gypsum and calcium bentonite. Apart from filling holes, one of the primary purposes is to mantle sacrificial anodes under the ground.
Backflow is the reversal of water flow through pipes due to siphonage or back pressure. A State Certified backflow device is required by law and protects your drinking water by preventing siphonage from your lawn back into your domestic water supply.