Contamination Barrier

Contamination Barrier is a landscaping structure that prevents the spread of contamination through soil by blocking contamination propagation in the Dirt blocks directly beneath it. It acts as a horizontal containment element: when placed over continuous ground, contamination will not pass from one side to the other through the dirt tiles under the barrier. The barrier does not alter irrigation levels of nearby land and therefore does not affect hydration or dryness of adjacent soil.

Contamination can spread diagonally, so Contamination Barrier must form an unbroken, solid wall against diagonal paths of spread to be fully effective. Gaps in the terrain under a barrier (for example, an empty space or missing dirt tile) stop its protective effect at that location. The barrier can be used on overhangs to prevent contamination from moving directly down into the layers below where it is placed, provided the ground beneath is continuous and without gaps.

• Contamination Barrier stops contamination spread only in the dirt blocks directly below it; it does not block contamination through non-adjacent tiles.
• Barriers do not change irrigation or soil moisture; they only affect contamination propagation.
• Contamination spreads diagonally; place barriers in continuous lines without gaps to block diagonal routes.
• Gaps in the terrain under a barrier will render that section ineffective.
• Barriers placed on overhangs still block contamination beneath them if the ground continuity requirement is met.

The item was introduced in Update 5. In Update 7 the barrier received a connected texture for clearer visual continuity and was changed so that placing barriers in a diagonal line no longer blocks other relevant ground effects. Visual examples show use on overhangs and demonstrate how gaps in the underlying terrain interrupt the barrier’s effectiveness.