Search results
Results from the WOW.Com Content Network
The major river in Ethiopia is the Blue Nile. However, most drinking water in Ethiopia comes from ground water, not rivers. Ethiopia has 12 river basins with an annual runoff volume of 122 billion m 3 of water and an estimated 2.6–6.5 billion m 3 of ground water potential.
Not to be exceeded more than once per year 40 CFR 50.5: Particulate matter (PM 10) Primary and Secondary 150 μg/m 3: 24-hour Not to be exceeded more than once per year on average over 3 years 40 CFR 50.6: Fine particulate matter (PM 2.5) Primary 9.0 μg/m 3 (12 μg/m 3 prior to May 6, 2024) [25] annual Annual mean, averaged over 3 years 40 CFR ...
A typical family on the US East Coast paid between US$30 and US$70 per month for water and sewer services in 2005. [15] In developing countries, tariffs are usually much further from covering costs. Residential water bills for a typical consumption of 15 cubic meters per month vary between less than US$1 and US$12 per month. [16]
" indicates that no standard has been identified by editors of this article and ns indicates that no standard exists. μg/L = micrograms per litre, or 0.001 ppm; mg/L = 1 ppm, or 1000 μg/L. * means action level; not a concentration standard. A public water system exceeding the action level must implement "treatment techniques" which are ...
This 3-hour PSI is unique to Singapore and was introduced in 1997 to provide additional air quality information which would better reflect a more current air quality situation. [3] In 2016, the 3-hour PSI was phased out on the grounds that the 1-hour PM 2.5 reading was a better indicator of the current air quality.
Air changes per hour, abbreviated ACPH or ACH, or air change rate is the number of times that the total air volume in a room or space is completely removed and replaced in an hour. If the air in the space is either uniform or perfectly mixed, air changes per hour is a measure of how many times the air within a defined space is replaced each hour.
In 2017 only 71 per cent of the global population used safely managed drinking water, and 2.2 billion persons were still without safely managed drinking water. Other water-related hazards related to flooding and drought also remain significant threats to human development and wellbeing.
The WHO first released the air quality guidelines in 1987, then updated them in 1997. [2] The reports provide guidelines intending to give guidelines to reduce the health effects of air pollution. [2]