Natural systems such as ponds, wetlands and soil infiltration systems (see also soak pits and nonplanted filters) are technically simple yet their performance is comparable and sometimes exceeds conventional technical systems. This lecture elucidates why natural system can work well even in cold climate and point to some key factors regarding sizing and design.
Case study about a combined pond / constructed wetland system in cold climate for 160 peoples, a dairy and food processing workshop, a bakery and a laundry. A vertical flow constructed wetlands was installed for pre-treatment, followed by a deep enhanced facultative pond, three aerated stabilization ponds, a planted sand filter and finally tow horizontal-flow constructed wetlands.BROWNE, P.D. ; JENSSEN, P.D. (2005): Exceeding Tertiary Standards with a Pond/Reed Bed System in Norway. In: Journal of Water Science and Technology: Volume 51 , 299-306. URL [Accessed: 03.06.2019]
Counts of indicator bacteria and pathogens can serve as parameters of purification. This paper addresses the topic of bacterial content of sewage and of key stages of treatment related to the quality of the effluents and their potential danger to groundwater.MCCOY, E. ZIEBEL, W.E. (1975): The Effects of Effluents on Groundwater. Bacteriological Aspects. (= (= Proceedings of the National Sanitation Foundation: Second National Conference on Individual Onsite Wastewater Systems in Ann Arbor, 5th-7th November 1975) ). Ann Arbor: URL [Accessed: 27.11.2012]
This document describes onsite wastewater soil absorption systems (WSAS), which have the potential to achieve high treatment efficiencies over a long life service at low cost. Information is given on the function and performance of WSAS, the current state of knowledge, and identifying major gaps in predicting system performance.SIEGRIST, R.L. TYLER, E.J. JENSSEN, P.D. (2000): Design and Performance of Onsite Wastewater Soil Absorption Systems. (= National Research Needs Conference, May 2000 ). St. Louis, MO: