protecting your drinking water: wells and septic...
Post on 13-Sep-2018
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Presentation overview
•What are chemicals of emerging concern?
•What is a good septic system?
•What is a good drinking water system?
•What can you do to project our water?
What are chemicals of emerging concern (CEC)?
• A contaminant is generally a substance that is in a place where it doesn’t belong
• CECs are substances that have been released to, found in, or have the potential to enter Minnesota waters (groundwater or surface water) and:• do not have Minnesota human health-based guidance (how much of a
substance is safe to drink)• pose a real or perceived health threat• have new or changing health or exposure information
• They can include pharmaceuticals, pesticides, industrial effluents, personal care products that are washed down drains
CECs continued
•New contaminants are being found in Minnesota waters. This is due, in part, because:• there are better methods for finding substances at
lower levels
• additional substances are being looked for
•new substances are being used
•old substances are being used in new ways
AntibioticsHormones (synthetic and natural)Metabolites (cotinine)Psychoactive drugsLipid regulatorsPain relieversFragrancesChemotherapy drugsFire retardantsCleaning productsothers
Examples of CECs
CEC units results
• Nanograms/liter
• 1 part per trillion
• 1 ng/l Analogy – 1 oz. in 7.5 billion gallons of water
http://bit.ly/2dy6BP7
Surface water study
• Sampled downstream of urban areas, intense livestock areas, wastewater systems
• Sampled for 95 CEC
•139 streams, 30 states
•82 of 95 detected
•80% of samples were contaminated
Tap water evaluation
•19 utilities serving 138 million people
•Sampled for 55 chemicals – found 11 most frequently at levels <10 ng/L
•Atrazine found ~40-50 ng/L
Survey of 19 US drinking water utilities
• Atenolol - betablocker
• Atrazine - herbicide
• Carbamazepine - anticonvulsant
• Estrone - hormone
• Gemfibrozil - antilipidemic
• Meprobamate – antianxiety
• Naproxen – anti-inflammatory
• Phenytoin – anticonvulsant
• Sulfamethoxazole - antibiotic
• TCEP - flame retardant
• Trimethoprim - antibiotic
Top 11 of 55 compoundsMedian concentrations generally < 10 ng/L
Benotti et al. ES&T 2009
Where do CECs come from?
• Personal care products
• Detergents
• Industrial discharge
• Residential wastewater
• Agriculture
How do we limit the impact of CECs on our individual properties?
•Good septic system
•Good well
•Proper management
•Product selection
Good septic systems
•No not backup into home
•No not surface in the yard or into a water body
•Have watertight septic tanks
•Protect ground water by having adequate vertical separation to saturated zone or confining layer
Public Health Risk Management
Who manages the risk?
•Federal Government-Public
•State Government-Public
•City-Public
•Restaurant, Resort, School, Church-Public
•Private owners-YOU!
Public drinking water systems in Minnesota
•Community Wells/Systems• Where people live
• Cities, Towns, Mobile Home Parks
•Noncommunity Wells/Systems• Where people go
• Resorts, Schools, Churches, Restaurants
• Non-transient• Transient
Community water systems
• ~1000 Community Public Water Supplies
• Source-Groundwater and Surface Water
• Provides water to 15+ connections or 25 people for six plus months
• 20 MDH Staff• District Engineer• Compliance Engineer• Compliance Officer• Hydrologist (usually; helps identify if new well is a compliance option) – SWP Unit• Enforcement Coordinator – Admin Unit• CPWS Unit Supervisor
Noncommunity water systems
• ~7000 Noncommunity Public Water Systems
• 37 MDH staff and Delegated program staff• Field Sanitarians• Compliance Staff• Support Staff• Unit Supervisors
• Nontransient• Serves 25 of the same people for 6 months +• Schools, Child Care, Offices, Factories
• Transient• Serves 25 people for 60 days +• Resorts, Restaurants, Campgrounds
Monitoring and testing
•Public Systems-Community and Noncommunity• In Minnesota these systems are tested for bacteria,
nitrate and other inorganic chemicals, radiological elements, and up to 118 different industrial chemicals and pesticides
• The exact list of contaminants—and the testing schedule—vary from one system to another
Monitoring and testing
•Public Systems Noncommunity Testing•Bacteria-coliform
•Nitrates
•Arsenic
• Lead
•Certified Labs
Inspection and maintenance
•Public Systems• Sanitary Survey (every 3 years)
• Wellhead
• Distribution System
• Wellhead Protection Area
Help protect your private drinking water system
•Drinking water monitoring and testing•Certified lab
• Inspect your drinking water system•Conduct your own Sanitary Survey
Private well testing - certified lab
•Bacteria-recommended to test annually
•Nitrates-recommended to test annual/bi-annual
•Arsenic-one time test
•Lead-one time test
•Manganese-one time test
Bacteria
•Bacteria-coliform•Coliform is an indicator of contamination
• Total coliform
• Fecal coliform
•Positive test result• Disinfect your well
• Licensed water well contractor
• Why? Recent work done on your plumbing?
• Inspect your drinking water system
Nitrates
•Test and track nitrate•10 ppm
• Infants and pregnant women
•Treatment•Point of use
•Drill a new well
Arsenic
•Tested for in all new wells since 2008
•How and why?•Geology (natural)•Man made (preservative)
•Treatment•Point of Use•Drill a new well
Arsenic
•Treatment• Point of Use
• Reverse Osmosis (RO) is a water treatment process that removes most dissolved, inorganic contaminants from water by forcing the water through a cellophane-like plastic sheet known as a “semi-permeable membrane.” A pre-oxidation step is usually necessary to convert all arsenic in the water to a removable form. A small counter top RO unit will produce about 3 gallons per day
• RO cost
• Drill a new well
Lead
Where does the lead come from?•Lead pipes•Lead solder - has been illegal in Minnesota since 1985•Brass components such as faucets, coolers, and valves - contains low lead levels but can still dissolve lead into the water, especially during the first few months of use•Lead "packers" above the well screen may have been used in wells that were drilled over 20 years ago•Some submersible pumps manufactured before 1995 may contain leaded-brass components. •Other plumbing components - Some trade agreements with foreign nations allow them to export plumbing components for sale in the United States that are not lead free
Lead Reduction
•Flush your system 30-60 seconds•Water plants• Store in fridge
•Use cold water for cooking and drinking
•Point of use treatment•Reverse osmosis•Distillation
Manganese
•Occurs naturally in groundwater
•No Federal or State regulations
•Pregnant Women
• Fetuses and infants
Manganese Reduction
•Promotion of breastfeeding
•Dry Formula• Bottle or tap water tested for manganese
•Carbon filter• Up to a 50% reduction
Your Well's Vulnerability
• Type• Shallow
• Deep
• Rock
• Pit or Basement
• Grouting-full length• Local geography• Local contamination issues
• Flooding
Your well inspection and maintenance
•Wellhead• Electrical connection
• Conduit
• Vent screening• Protection
• Vehicles, lawn mowers, ATVs
• Casing• Grading
Water system inspection & maintenance
•Distribution System• Cross connections-Air gaps and backflow prevention devices
• Treatment unit-Water Softener• Boiler• Outside hose connections
• System Maintenance• Treatment units
• Water softener • Pressure Tank
• Pump running?-check leaks or dripping/running fixtures• Deadhead pipes-remove
Distribution System Leaks, Devices, and Pipes
• Toilets and Faucets
• No dripping and running allowed!
• Treatment Devices• Manufacturer Recommendations
• Clean/replace carbon filters
• Water Softener• Salt
• Brine Tank
• Remove dead end pipes
Your well zone inspection
•Your wellhead protection area•What’s in your yard?
•What’s in your neighbor’s yard?
•Unused wells on the properties?• Seal (check for local funding programs)
• Licensed water well contactor
Nature conserves valuable work. Many of the metabolic and regulatory pathways that have evolved are conserved between classes of organisms.
This means that many of the drugs we invent to regulate our metabolic systems can also effect “lower” organisms and sometimes visa versa.
YOU ARE HERE
Earliest indication of the presence of estrogen
and estrogen receptors
Many hormones are regulated by feedback loops where the concentration of the hormone limits its further production.
Some CEC “lock into” receptors and hence may sent the wrong signal to the body, either shutting off or ramping up the production of the hormone.
Bacteria - you may not like them
• But we need these guys
• bacteria and fungi are the workhorses of wastewater treatment
• they prefer their carbon source to be non-toxic
They are exposed to everything we put down the drain
• The good news
• Most waste organic compounds can be degraded by the microbes
• in the septic tank
• in the soil
• The bad news
• there are plenty of organic compounds that will kill them
Antibiotics and Similar Meds
• Antibiotics are not selective in which bacteria are killed
• While antibiotics help a patient by killing harmful bacteria, the medicine often kills good bacteria also
• Recommendations: Use them only when needed, dispose of unused ones properly (Do NOT flush)
Attenuation RemovalAttenuation vs Removal
• Adsorption
• Conjugation (with possibility of deconjugation)
• Chemical breakdown
• Biodegradation
Bacteria/gram of soil
7-8 million
1- 2 million
400 – 500 thousand
~ 10 thousand
one thousand
hundreds
Billions
Bacteria (and other microbes) – the real workhorses of the terrestrial ecosystems
1
10
100
1000
10000
100000
Influent(range)
STE(range)
Percolate(p=.05)
Influent(range)
STE(range)
Percolate(p=.05)
Sulf
amet
ho
xazo
le (
ng
/L)
DRIP DISPERSAL SHALLOW DRAINFIELD
98% reduction
97% reduction
Removal in conventional activated sludge treatment plant 59% (37 – 80%)
0.1
1
10
100
1000
Influent(range)
STE(range)
Percolate(p=.05)
Influent(range)
STE(range)
Percolate(p=.05)
Dic
lofe
nac
(ng
/L)
DRIP DISPERSAL SHALLOW DRAINFIELD
89% reduction
99% reduction
Removal in conventional activated sludge treatment plant 31% (13 - 60%)
1
10
100
1000
Influent(range)
STE(range)
Percolate(p=.05)
Influent(range)
STE(range)
Percolate(p=.05)
Ato
rvas
tati
n (
ng
/L)
DRIP DISPERSAL SHALLOW DRAINFIELD
92% reduction
91% reduction
Compound Drip
Shallow
Drainfield
Conventional
activated sludge
treatment
Acetominophen 99.99% 99.82% > 90% - 99.9% (b)
Atenolol 93.62% 99.03% 5.5% ( 2-20%)(a)
Atorvastatin 92.60% 91.18% 85-95% (d)
Caffeine 99.97% 99.93% 94.9% (c )
Ciprofloxacin 97.96% 98.17% 72% (59-85%)(a)
DEET 98.45% 98.24% 69% (48-90%) (e )
Diclofenac 89.16% 99.37% 31% (13-60%)(a)
Furosemide 97.60% 98.40% 59.8% (c )
Ibuprofen 99.94% 99.93% 74%(44-100%)(a)
Miconazole 0.00% 0.00%
Naproxen 99.50% 96.80% 75% (59-92%)(a)
Propranolol 71.20% 96.89% 96% (a)
Sulfamethoxazole 97.90% 96.50% 59% (37-80%)(a)
TCEP 0.00% 0.00%
Trimethoprim 99.20% 99.80% 14% (0 - 40%)(a)
•Neither shallow soils systems or conventional treatment systems appear to be effective for the removal of:• Fire retardants (TCEP)
•Anti-fungal medications
1
10
100
1000
10000
100000
Influent
(range)
STE
(range)
Sand
(p=.05)
Sand w/ 5% fines
(p=.05)
Sand w/ 10%
fines
(p=.05)
Su
lfam
eth
oxazo
le (
ng/L
)
Soil column research
Factors affecting the attenuation or removal of CEC in wastewater treatment
• Nature of the compound
• Oxygen availability
• Bacteria and other fauna diversity in the receiving environment
• Retention time during treatment
Take home messages
• Many pharmaceutical and personal care products, contain compounds that can disrupt the normal functioning of hormones in humans and wildlife
• Although a major route for CEC entrance into the environment is wastewater disposal, the onsite septic system presents opportunity for significant treatment
• Shallow-placed soil absorption systems remove > 90% of many CECs found in household wastewater
• A more complete understanding of the principles of CEC removal in soils may offer opportunities to design optimization
• Make sure your management plans include a discussion on CECs
What can you do?
•Water conservation
•Properly operation and maintenance your septic and well systems
•Proper disposal of unused pharmaceuticals and hazardous waste
•Be informed and get involved
Additional resources
http://www.health.state.mn.us/topics/water
Septic Systemswww.septic.umn.edu/
https://www.pca.state.mn.us/water/
Water and Health
Water and Health
EPA CEC program http://bit.ly/29PUcFv
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