Pollution

The introduction of harmful contaminates into the natural environment that can cause adverse changes.

As citizens burn fuel to cook or generate power, smelt metals, process sewage, and engage in countless other necessary industrial activities, a common byproduct is pollution. Pollution is any substance that can act as a contaminant or poison when introduced back into the environment. In Eco there are many sources and several varieties of pollution, some of which are more potent than others. Heavy metals can contaminate soil, affecting available nutrients and the health of plants and animals living on and in it. Water can spread contaminants rapidly and increase the size of their impact. Air pollution can pour invisibly or visibly from a stove or a power plant, adding to greenhouse gasses and impacting the air quality, as well as fall back down into the ground as acid rain.

To ensure the survival of ecosystems and preserve resources like soil and water, players have to manage and contain the sources of pollution their civilization creates. Some spills and dangerous concentrations are inevitable, and when they happen containment, storage and remediation are what return the land to an unharmed state.

Ground Pollution

Ground pollution is tracked claim by claim, in four separate layers: Soil, Heavy Mineral, Chemical and Acid Rain. Every polluting block left in the world adds a flat 0.1 to the layer it belongs to, so ten blocks of TailingsItem sitting on a claim will drive that claim's Heavy Mineral Pollution to 100%. Layers do not jump to that figure, they converge on it over roughly three days, so a spill takes time to show its full effect, and time to fade once you have dealt with it. Only the horizontal position of the waste matters. Burying it changes nothing.

Waste that a machine has just produced is granted a day of grace before it begins to pollute, which is time enough to cart it to a sorter or a proper container. Waste that was not produced but simply dropped in the world pollutes from the moment it lands.

The Ground Pollution map you can call up shows the sum of the four layers, spread outward from every contaminated claim. Plumes fall off with the square of the distance and they add together, so three neighbouring claims at 100% read, from a distance, exactly like a single claim at 300%. Their reach grows with the square root of the value: ten times the pollution carries about three times as far. A poisoned claim is never a private problem for long.

The Four Layers

Soil Pollution is the waste of everyday life: MixedGarbageItem, trash and sewage. It is the mildest of the four, and the only one that always cleans itself in time, however high it has climbed.

Heavy Mineral Pollution comes from mining and mineral processing, above all TailingsItem and WetTailingsItem. It only self-cleans up to 100%. Past that the ground is saturated and will never recover on its own.

Chemical Pollution is the mark of heavy industry, from ChemicalWasteItem and the chemical byproducts of advanced crafting. It is by far the least forgiving, plateauing at a mere 30%. Let a claim climb past that and it stays poisoned until you treat it.

Acid Rain Pollution is the one layer you never dump: it falls. Where air pollution meets rainfall, acid rain forms and settles into the ground below. How sour a claim gets depends on how much its chimneys emit and on how wet the region is — a blast furnace running day and night will hold its own claim at twice the full gauge in an average climate, but at a fifth of that in a desert, so where heavy industry goes is a decision worth making. It is also the one layer you never need to treat: it halves every six hours once the smokestacks go quiet, so cutting emissions is the whole answer.

Air Pollution

Many player activities create harmful emissions which if released into the atmosphere act as air pollution. Crafting at objects with CO2 outputs or running generators with them contributes to local and global pollution levels. Over long periods of time, global CO2 levels contributes to a global warming effect which affects sea level in turn. There are natural sinks and intakes for some pollutants like CO2 such as forests.

Where air pollution meets rainfall, it comes back down as acid rain and feeds the Acid Rain layer of the claim it was emitted on — which then spreads outward like any other ground pollution. Emissions are therefore never only an air problem: an unfiltered smokestack slowly sours the land around it, and a row of them sours it together.

Water Pollution

Water holds no pollution of its own; it carries what the ground gives it. Where a plume reaches water it travels roughly three times further than it would over land, and arrives correspondingly diluted, a long weak tail drawn out across a lake or into the open sea. A tailings pile on a riverbank contaminates a great deal more than the riverbank.

Pipes are the other way water becomes a problem. An effluent released from an open pipe end poisons the ground where it lands, each fluid feeding its own layer: SewageItem fouls the soil, IndustrialSewageItem carries heavy metals, and ChemicalWasteFluidItem is caustic enough to be in a class of its own. Run them into a WasteFilterItem instead and they come out as WaterItem, clean enough to release or reuse, with the solids they carried captured for you to store or recycle.

Because open water only reflects its sources, there is nothing in it to scrub out directly. Contain or remove the sources on the shore, remediate the claims that feed it, and the water clears along with them.

Containment

Storing polluting material properly is the cheapest way to keep it out of the ground. A polluting block dumped in the open contributes its full amount, and so, be warned, so does the same material sitting in an ordinary chest: only purpose-built containment holds anything back. A PrimitiveBinItem keeps 20% of what it holds out of the soil, an ModernGarbageBinItem 60%, and a DumpsterGarbageItem 90%. None of them is perfect: a large enough dump will still poison the claim it stands on, however well it has been packed.

Producing less waste to begin with is the other half of the answer. A GarbageSorterItem separates mixed garbage into materials that can be recycled and put back to use, and a ResidualWasteSorterItem does the same for the residuals of industry, leaving a smaller volume of genuinely unusable waste behind. Space must still be made for what remains, and where that space goes should be a deliberate decision of your society rather than an accident of where the carts stopped.

Remediation

Land that has already been poisoned can be treated. Decontaminants are consumables applied much like fertilizer, on any block of a claim — bare ground, a road, or the floor of a factory: a SoilDecontaminantItem for soil, a HeavyMineralDecontaminantItem for heavy metals, and a ChemicalDecontaminantItem for chemical contamination. One unit cancels one unit of pollution source, doses stack, and half of what is waiting on an area takes effect every 24 hours, so a badly contaminated claim can be treated in bulk and left to soak.

Decontamination is also the only thing that works past a layer's self-cleaning ceiling. A claim above 100% Heavy Mineral, or above 30% Chemical, will sit there indefinitely otherwise, whether or not the source has been removed. Every decontaminant cleans at the same rate, so the cost is what separates them: compost and dirt clean soil, clay and coal bind heavy metals, and iron and coal go into every chemical neutralizer. Cleaning up after heavy industry is meant to be expensive. Not cleaning up is meant to be worse.