Access to water and sanitation can be particularly challenging for people who are already vulnerable or marginalized, including children, people with disabilities, and people with HIV. Often people in these groups must rely on others for help with basic needs, such as collecting water, going to the toilet, and bathing, because accessible services are not available. Since it has been well documented that vulnerable groups disproportionately shoulder the burden of inadequate water and sanitation, international law seeks to protect these groups by putting special obligations on states to ensure that these basic services are offered without discrimination, and can be accessed by all people.[44]