The latest figures for wastewater treatment in Europe show improvements in collection and treatment, even if big differences remain between the 28 EU member states, the European Commission said in a report released Wednesday. This progress comes with significant EU investment support, amounting to EUR 14.3 billion between 2007-2013, it noted. Under the 1991 EU legislation, member states are obliged to have systems for collecting urban waste water in place, and they have to ensure that water entering collection systems undergoes appropriate \"secondary\" treatment to remove pollutants. Wastewater entering sensitive areas (such as bathing sites or drinking water reservoirs) must undergo an additional more stringent form of treatment. The report said that 15 EU Member States are collecting 100 % of their total polluting load. All EU members states had maintained or improved previous results, although compliance rates remained below 30 % in Bulgaria, Cyprus, Estonia, Latvia and Slovenia. Untreated waste water can be contaminated with harmful bacteria and viruses and thus presents a risk to public health. It also contains nutrients such as nitrogen and phosphorous which can damage freshwaters and the marine environment by promoting excessive growth of algae that chokes other life.