Chalillo Dam

Water Quality Update for the Macal River

Belize Department of the Environment

October 15, 2009

Press Release from the government: 

On August 18, 2009, a team of officials from the Department of the Environment, the Geology and Petroleum Department, the Public Health Department, and NEMO (San Ignacio) conducted a site visit at the Chalillo Impoundment in relation to the sedimentation issue occurring over the past few months.  Samples of water were taken at four locations: in the Chalillo Impoundment (upstream); in the tailrace of the Chalillo Dam; at Cristo Rey Village; and in San Ignacio Town.  These samples were sent to PACE Analytical Laboratory in Louisiana, USA, to be analyzed for a total of 13 heavy metals including aluminum, arsenic, barium, cadmium, copper, iron, lead, magnesium, manganese, mercury, nickel, selenium, and zinc.

The results of these tests showed high concentrations of iron in the impoundment area of the dam and in the tailrace area. However, further downstream at Cristo Rey and San Ignacio Town, no iron contamination was detected.  Iron contamination in water presents mainly an aesthetic concern as it causes a reddish-brown discoloration of the water.

Trace levels of aluminum, lead, and manganese were detected in the impoundment and tailrace area of the Chalillo Dam, but the levels were too low to be of any health concern.  For the remaining nine parameters (arsenic, barium, cadmium, copper, magnesium, mercury, nickel, selenium and zinc) none were detected in any of the four samples.

The Department of the Environment (DOE) and the Ministry of Health would like to take this opportunity to reassure the general public that the sedimentation of the Macal River poses no health hazard insofar as heavy metal contamination is concerned. The DOE and the Ministry of Health continue to work in close cooperation with other relevant government agencies in monitoring the state of the Macal River.

For more information on the tests, read this article from Amandala.

Is your water safe? DOE releases heavy metals test results

Manganese above widely accepted drinking water standard
by Adele Ramos

The Department of the Environment today responded to our request for the results of the laboratory tests sent to Pace Analytical Services in Louisiana, USA, for 13 signal heavy metals in waters taken from the Macal River on August 18, when the waters changed to a muddy coffee-with-milk coloration. The results we received are for samples starting at the Chalillo site and ending at San Ignacio, and they indicate the presence of manganese above the reporting limit.

Of note is that arsenic, barium, cadmium, copper, mercury, nickel, selenium and zinc, were not detected in the samples. However, there were high levels of aluminum at Chalillo, but none detected at Cristo Rey Village and San Ignacio.

Lead and iron were detected above the reporting limit at both Chalillo sites, only.

On the other hand, manganese (a naturally occurring substance and an essential nutrient which is also present in some foods) was detected above the reporting limit at both Cristo Rey and San Ignacio, as well as at the Chalillo impoundment.

According to the US Department of Health and Human Services, Agency for Toxic Substances and Disease Registry, the US Environmental Protection Agency (EPA) had established that drinking water should not contain more than 0.05 milligrams per liter of manganese. The water tested at San Ignacio contains 61.6 µg (micrograms) or 0.0616 mg (milligrams) per liter – above the bottled water limit.

According to the World Health Organization’s Manganese in Drinking-water: Background document for development of WHO Guidelines for Drinking-water Quality (2004), “A number of countries have set standards for manganese of 0.05 mg/litre, above which problems with discoloration may occur.”

It added that, “In the USA, the National Inorganic and Radionuclide Survey collected data from 989 community public water systems served by groundwater in 49 states between 1984 and 1986 and found that manganese was detected in 68% of the groundwater systems, with a median concentration of 10 µg/litre. Supplemental survey data from public water systems supplied by surface water in five states reported occurrence ranges similar to those of groundwater. In Germany, the drinking-water supplied to 90% of all households contained less than 20 µg of manganese per litre (Bundesgesundheitsamt, 1991).”

Manganese could be a concern if existing in harmful quantities because it has been linked to violent behavior, and is linked to behavioral and mental changes in children, including learning deficits and memory loss.

We reproduce the Pace laboratory results provided to us by the DOE in the table below:

 

Units: µg/L 

Reporting
Limit

Chalillo
Impoundment

Chalillo
Tailrace

Cristo Rey
Village

San Ignacio Town
(near wooden bridge)

1

 Aluminum

200

1960

1910

ND

ND

2

 Arsenic

10

ND

ND

ND

ND

3

 Barium

200

ND

ND

ND

ND

4

 Cadmium

5

ND

ND

ND

ND

5

 Copper

10

ND

ND

ND

ND

6

 Iron

100

3700

3800

ND

ND

7

 Lead

5

10.2

6.13

ND

ND

8

 Magnesium

5000

ND

ND

ND

ND

9

Manganese

15

44.3

ND

54.6

61.6

10

 Mercury

0.2

ND

ND

ND

ND

11

 Nickel

40

ND

ND

ND

ND

12

 Selenium

35

ND

ND

ND

ND

13

 Zinc

20

ND

ND

ND

ND

Categories: Chalillo Dam

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