public abstract class TreatmentPlant {
	protected Town town;
	protected double x;		// Fraction pollutants removed
	private int ID;
	private static int nextID=0;
	public static double MAX_CONCENTRATION= 20;		// Mg/L
	
	public TreatmentPlant() {
		town= null;
		x= 0;
		ID= nextID++;
	}
	
	public TreatmentPlant(Town t, double x) {
		town= t;
		this.x= x;
		ID= nextID++;
	}
	
	public abstract double getCost();
	public abstract double getMaxRemoved();
	public abstract double getArea();

	public final int getID() {
		return ID;
	}
}