Excreta management is gender-segregated and often racially differentiated. A 2014 Human Rights Watch report on the caste and gender profile of manual excreta cleaners in India revealed that 95% of private and village latrines were cleaned by women; both women and men cleaned open defecation from roads, open areas and open gutters, while men typically cleaned septic tanks, closed gutters and sewers (HRW 2014). These systems range from natural approaches such as the use of ponds and constructed wetlands (which are low-tech and low-maintenance) as filters and for cleaning wastewater, to high-tech vacuum biogas installations.