Water QualityWater QualityWater QualityWater QualityNREM 461NREM 461

Dr. Greg Bruland

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I. Water Quality

A. Variability in Water Quality

1. Surface vs groundwater

a. Which has more variable WQ? Why?

2. Standards different for industrial, irrigation, drinking water useswater uses

a. What use has strictest standards? Why?

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B. Types of Water Pollutants

1. Sediments: eroded soil supplies more material than any other pollutant

US t 700X h di ta. US streams carry 700X as much sediment as sewage

b. Problems last longer in

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c. Sources:c. Sources: ag, forestry, land clearing, construction

d. Effects:• fills in streams, channels, reservoirs, estuaries, harbors & ↑

flooding; • ↑ turbidity,↓ light penetration, ↓ PSN by corals, SGs, SAV;• smothers coral reefs & SG beds; • irritates, clogs fish gills; • carries nutrients & pesticides

e. BMPs:

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f. pesticides carried by sediment widely distributed in streams, lakes, oceans

i. insecticides more common in ________, herbicides in __________ regions

Photo courtesy of USDA NRCS

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2. Nutrients: N & P most problematic

a. Human health concern: High NO3- conc. in drinking H2O cause

methemoglobinemia,

b. Sources:

ag sewage animal wastes urban lawns atmo depag, sewage, animal wastes, urban lawns, atmo. dep.

c. Effects:c. Effects:

• phytoplankton, toxic algal blooms, eutrophication;

• hypoxia, anoxia, fish kills; yp , , ;

• degradation of coral & SG habitat;

• disruption of aquatic/coastal food webs

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Algal Bloom at Waimanalo Beach - 9/23/977

d. BMPs:

8Photos courtesy of USDA NRCS

3. Heat: easy to overlook, can be serious as O2 much less soluble in H2O w/ ↑ tempw/ ↑ temp

a. Sources:• industrial use of H2O as a coolant & return of heated H2O toindustrial use of H2O as a coolant & return of heated H2O to streams • ag. irrigation: cool, clear stream water → warm, turbid• sunlight on shallow H2O w/ lack of shading 2

b. Effects:↓ in dissolved O2;interferes w/ reproduction: salmon, trout require cool H2O for habitat & spawning;

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c BMPs:c. BMPs:

diffusers

air cooling towers

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4. Organic pollutants: sewage, manure, & petroleum products

a. Sewage:

i. Sources:i. Sources: • some cities dump raw sewage into streams, • rural/urban cess pools,• many dump sewage during peak flows, disasters, plant malfunctions,• laundry det. & cleaning agents

ii. Effects:human health & eco-healtheutrophication

iii. BMPs:

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Sewage Treatment

Primary: removes solid materialsPrimary: removes solid materials

Secondary: allows microbes to decompose OM

Tertiary: required to remove nutrients, other dissolved ions

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Septic SystemSeptic System

b. Manure: does not pass thru sewage treatment, often has high fecal contam.co ta

i. Sources: feedlots, confinement housesfeedlots, confinement housesmanure pilesanimal operations

ii. Effects: human health concernseutrophicationodor/air quality

iii. BMPs:

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c. Petroleum Products: used in large amounts, low biodegradablityo b odeg adab ty

i. Sources: Spills of crude oil, motor oil, gasolineDiscarded plasticsOcean vessel maintenanceNatural seeps

ii. Effects:Acute & chronic toxicity to aquatic/coastal/ marine organismsmarine organismsContaminate food websDisrupt chemical signaling

iii. BMPs:

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5. Heavy Metals: Many are micronutrients, toxic at high conc.

a. Arsenic ( ): oxidized As( ) harmless, reduced As( ) toxic

i Sources:i. Sources:

rat poisons, herbicides, insecticides, wood preservativeswood preservatives

ii. Effects:

neurological damage, stomach disorders, death

iii. BMPs:

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b. Cadium ( ): less abundant, wide dist, toxic at low conc.

i. Sources:

Mi l d itMineral deposits, Used in galvanized coating to protect Fe from rustNicad batteriesPottery glazePottery glaze

ii. Effects:

Kidney & liver damage

iii. BMPs

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c. Copper ( ): micronutrient & toxin, long used as pesticidec Coppe ( ) c o ut e t & to , o g used as pest c de

i. Sources:

pesticides, highway runoff

ii. Effects:

interferes w/ respiration of fish

iii BMPsiii. BMPs

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d. Lead ( ): multiple uses, 1 of most common causes of d ead ( ) u t p e uses, o ost co o causes ometal toxicity in H2O

i. Sources:

lead goblets; lead pipes, fixtures, solder, & paint;

ligasoline; car batteries; hunting-lead shot; fishing sinkersfishing-sinkers

ii. Effects:

toxic to aquatic orgs & humans; effects brain, behavior, growth

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iii. BMPs

ban Pb in gasoline in 80s

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e. Mercury ( ): aka

i. Sources:

th t li ht it h b tt i i t i ti id tthermometers; light switches; batteries; paints; insecticides; rat poisons; Cl & NaOH prod., fossil fuel combustion, mining

ii Effects:ii. Effects:

skin & organ damage; Minamata Japan Hg poisoning in 1950sMinamata, Japan, Hg poisoning in 1950s

iii. BMPs

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f. Nickel ( ): micronutrient & toxin

i. Sources:

Prod. of stainless steel & plating metalProd. of stainless steel & plating metalNiCad batteriesPetroleum products

ii. Effects:

Disrupts metabolism; Possible carcinogen

iii. BMPs

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C. Acidification of H2O & Soil

1. Acid deposition

a. Types

i. Wet (dep): rain, snow, mist, hail

ii Dry (dep): dust particulate aerosols smogii. Dry (dep): dust, particulate, aerosols, smog

b. Major Cause:

i. SO2 emissions

Nat. sources: volcanoes, sea spray, soil microbes, , p y, ,vegetation

Anthropo. sources: combustion of

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hydrocarbons, copper smelting, fires,

c. How acid effects soil & water:

i. Damage to plants

ii. Alteration of soil, H2O chemistry: ↓ in acid neutralization capacity of soil, H2Ocapacity of soil, H2O

Effects of acid rain on conifer forest

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D. Groundwater (GW) Contamination

1. Occurs when soluble ions like nitrates leach thru soil, & when SW carries pollutants thru wells, cracks, earthworm channels to GW

2. Feedlots, drainage wells, waste disposal sites are potential locations for GW contamination

3. BMPs:

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