On the operational side, sewers have to be flushed occasionally with injected drinking water in order to prevent stagnation of raw sewage.

On the environmental side, in some cities such as Berlin water tables are rising and cause damage to the foundations of buildings because of decreased pumping of groundwater by utilities.

The length of the sewer network in 2004 was estimated by the Federal Statistical Office to be 515,000 km, divided as follows: There were 9,994 wastewater treatment plants in Germany in 2004.

Unlike public water supply, sanitation is considered a sovereign core responsibility (hoheitliche Kernaufgabe) of municipalities in Germany.

The largest privately owned public water company is Gelsenwasser AG, although 92,9% of it are still owned by various municipalities,[16] which is a multi-utility company (water, sanitation and natural gas distribution) serving 3.2 million inhabitants in North Rhine-Westphalia, under concession agreements with 39 municipalities, and many other localities throughout Germany and internationally.

The organization of public water supply and sanitation, however, remains a prerogative of EU member states.

The German states (Länder) play a key role in the sector by setting, among other things, the legal framework for tariff approvals.

Municipalities, legally entrusted with service provision, play an indirect role in influencing policy positions related to water and sanitation through their influential municipal associations (the Deutsche Städtetag representing the largest cities and towns and the Deutscher Städte- und Gemeindebund representing smaller cities and towns).

In city-states (Berlin, Hamburg, Bremen) this means that the Minister (called Senator) of Economy both requests the tariff increase in his capacity as chairman of the board of the utility and also approves it, which constitutes a conflict of interest.

In the case of some private utilities, tariffs are set by a mutually agreed arbitrator based on the professional opinion of an auditor.

Drinking water quality is monitored by the public health departments of municipalities and counties (Landkreise).

In particular the two professional associations play an important role assisting in the development of technical norms and, more recently, in performance benchmarking.

In reaction to the liberalization debate the German Federal Parliament (Bundestag) passed a decision sponsored by the Green party and the Social-democrats (SPD) on sustainable water supply and sanitation (nachhaltige Wasserwirtschaft) in 2001.

[26] The study states that its methodology allows for an accurate comparison, including water used to flush pipes and for firefighting.

[27] The professional associations DVGW and DWA have jointly established a voluntary benchmarking system, which keeps individual company data confidential.

By law (Kommunalabgabengesetze or Betriebsgesetze der Länder) tariffs must cover the full costs of water supply and sanitation, including capital replacement and the remuneration of equity.

The various state laws do not foresee a review of the level of the efficiency of investments and operations as part of the tariff approval procedure.

The discharge fee is supposed to provide an incentive to treat water beyond what is legally required (Abwasserabgabengesetz).

However, according to a study commissioned by the German industry association BGW in 2006, the average household water bill was only 82 euro per year in Germany, lower than in France or in England and Wales, but higher than in Italy.

Comparison of annual water and sanitation bills per capita in four EU countries Source: Metropolitan Consulting Group: Vergleich europäischer Wasser- und Abwasserpreise, 2006 [25] Concerning sanitation, unequalized tariffs are by far the highest in Germany at 111 euro per year.

The development Bank KfW also provides long-term credit for up to 30 years (Kommunalkredit) for municipal investments, including water supply and sanitation.