RESULTS OF MONITORING OF ARSENIC
REMOVAL EQUIPMENT
IN
HUDSON, NEW HAMPSHIRE
Prepared by
Region I, Drinking Water Branch
U.S. Environmental Protection Agency
January, 1982
-------
OCLC Connexion
Page 1 of 1
OCLC 1141755330 Held by EHA - no other holdings
Rec stat n Entered 20200224 Replaced 20200224
Type a ELvl K Srce d Audn Ctrl
BLvl m Form Conf 0 Biog MRec
Lang eng
Ctry mau
Cont GPub f LitF 0 Indx 0
Desc i Ills a Fest 0 DtSt s Dates 1982 ,
040 EHA #b eng #e rda *c EHA
088 EPA 901-R-82-005
099 EPA 901 -R-82-005
049 EHAD
245 0 0 Results of monitoring of arsenic removal equipment in Hudson, New Hampshire / *c prepared by
Region I, Drinking Water Branch, U.S. Environmental Protection Agency.
264 1 [Boston, MA]: #b U.S. Environmental Protection Agency, Region I, Drinking Water Branch, *c 1982.
300 11 pages: *b figures, graphs ; *c 28 cm
336 text +b txt +2 rdacontent
337 unmediated #b n +2 rdamedia
338 volume *b nc +2 rdacarrier
500 Cover title.
500 "January, 1982."
650 0 Drinking water *x Arsenic content *z New Hampshire.
710 1 United States, ib Environmental Protection Agency. *b Region I. *b Drinking Water Branch, *e
Delete Holdings- Export- Label- Produce- Submit- Replace- Report Error- Update Holdings- ^g^ate q
issuing body.
C
Workflow-In
Process
about:blank
2/24/2020
-------
1.0 INTRODUCTION
Under the Safe Drinking Water Act (SDWA) of 1974, national standards for
the quality of public drinking water supplies were established to protect
public health. Routine chemical analyses of public drinking water sup-
plies in Hudson, New Hanpshire, as required by the SDWA, indicated
that several wells had arsenic concentrations exceeding the national
standard of 0.05 milligrams per liter (mg/1) recorrmended for drinking
water. As a result of these findings the State of New Hanpshire con-
ducted additional arsenic testing of approximately 200 domestic (private)
water systems in the Hudson vicinity to determine the scope of the
contamination between April 1980-January 1981, Approximately 10% of
those 200 samples contained arsenic in excess of the national standard,
ranging from 0.05 mg/1 - 0.37 mg/1.
The Town of Hudson and several bordering tcwns made arrangements with
private laboratories for the testing of water samples from private wells.
The towns coordinated the collection of water samples and the compilation
of the results. The analyses were paid for by the well owners. The re-
sults of these 1000 plus analyses indicated that approximately 10% of
these sanples contained arsenic in excess of the national standard,-
ranging from 0.05 mg/1 to 0.620 mg/1.
The occurrence of elevated arsenic concentrations in water supplies in
New Hampshire is an issue of current pubilc concern. It is important
to note, however, that EPA's authority under the Safe Drinking Wter
Act of 1974 extends only to public water systems (serving 25 or more
people). Because the elevated arsenic levels are found predominantly
in domestic (private) water supplies which are not under federal juris-
diction, EPA was greatly limited by the availability of funds and
personnel to undertake a large scale study. However, from a public
health aspect, EPA agreed to provide support in three areas of major
public concern: to provide analytical assistance to the Centers for
Disease Control (CDC) for their epidemiological study; to conduct an
investigation to determine the source of arsenic contamination; and
finally to provide analytical support for a pilot project to evaluate
the effectiveness of various available home treatment devices in re-
ducing arsenic concentrations.
In May of 1981, EPA published a report summarizing the investigation of
arsenic sources in the groundwater of the Hudson, New Hanpshire area.
This report concluded that the arsenic is coming from natural sources
in the bedrock of the area. As the source of the arsenic cannot be
removed, EPA has monitored the effectiveness of various home water
treatment units in removing arsenic from drinking water. The results
of this monitoring program are presented in this report.
2.0 EQUIPMENT MONITORED
Seven models of home treatment systems were installed and monitored in
four homes using three water sources, all bedrock wells. The systems
installed were:
-------
-2-
0 Reverse Osmosis with an activated alumina cartridge (R.O. + A.A,)
° Reverse Osmosis with an ion exchange cartridge (R.O. + I.X.)
° Fractional Distillation (F.D.)
° Two models of granular activated carbon (A.C.)
° Ion Exchange (I.X.)
° Activated Alumina (A.A.)
A sampling tap installed between the reverse osmosis membrane and the acti-
vated alumina cartridge in the first system permitted the monitoring of
the effectiveness of a R.O. unit by itself. Thus, eight systems were
monitored during this study. The cost for the systems installed
ranges fran $200 to $700.
All of the systems were installed according to the manufacturers'
instructions; several of the systems were installed by manufacturers'
representatives. A list of the manufacturers and the equipment used is
provided in Appendix A.*
Limitations of these systems include variability of water pressure during
the normal pump cycle and the naturally occurring impurities in the water.
Installation of the systems began on April 14, 1981. Due to difficulties
in obtaining an activated alumina system, the installations were not com-
pleted until early July. Monitoring of the sytems began on the day after
installation and continued until the end of October, 1981.
The water sources used during this program all had arsenic concentrations
greater than 0.2 mg/1 during initial analyses.
2.1 Water Source I
Water Source I is a drilled bedrock well which serves four housing units.
Two of these units were available for installation of treatment equipment.
A total of 4 treatment units were installed on this water source.
2.1.1 Treatment System I
This system consists of a reverse osmosis (R.O) unit followed by an acti-
vated alumina cartridge. (Figure 1) A sairpling point installed after the
R.O. membrance allowed the monitoring of the R.O. unit by itself. The
system was installed in the cabinet under the kitchen sink.
ftus system works by water pressure and requires no electricity to func-
tion. Product water is delivered to a separate tap installed on the
sink. The system generates 2-4 gallons of product water per day and
an equal amount of wastewater, depending on the water pressure. A
minimum water pressure of 40psi is recommended by the manufacturer.
*Mention of trade names or commercial products does not constitute
endorsement or recommendation for use by U.S. Environmental Protection
Agency; removal capability may vary with the chemistry of the raw
water.
-------
-3-
The plunfoing connections necessary are a tap on the cold water line for
supply and a connection to the drain for waste. Impurities and suspended
solids from the R.O, membrane and unused treated water are discharged to
the waste line.
The reverse osmosis membrane and the activated alumina cartridge are re-
moved and replaced when the system is clogged as evidenced by a decrease
in quantity of the product water.
2.1.2 Treatment System 2
This system is similar to the first system except that an ion exchange
cartridge is installed in place of the activated alumina cartridge
(Figure 2).
The operation and plumbing connections are identical to System 1. Again,
2-4 gallons of product water and a similar quantity of waste water are
generated each day at 40 psi water pressure.
2.1.3 Treatment System 3
System 3 is a fractional distillation system (Figure 3a). This system
is a wall mounted system requiring a cold water connection and a waste
connection to dispose of water used to flush the boiling chamber.
The fractional distillation system uses electricity to boil water to va-
por which condenses and flows by gravity to a collection container. As
the system is not presurized, water must be poured from the collection
container for use. Approximately 5 gallons of product water is generated
each day.
2.1.4. Treatment System 4
System 4 is an activated carbon system. The unit was mounted in the cab-
inet under the kitchen sink {Figure 3b). The system works by water pres-
sure and requires only a cold water connection and delivers the product
water through a tap mounted on the sink. Water is produced on demand
(about 1 gallon per minute (gptn)) with no daily limit due to equipment
operation.
2.2 Water Source II
Water Source II is a drilled bedrock well which supplies a single family
home. Two treatment systems were installed in this heme.
2.2.1 Treatment System 5
System 5 is an ion exchange unit which treats all of the water supplied
to the coldwater system in the kitchen (Figure 3c). The system is in-
stalled in-line in the basement and produces water as needed through
the coldwater faucet. As a part of System 5, a water softener was
installed and treats all of the water used in the home.
-------
-4-
Water pressure from the well pump runs the unit and no electricity is
needed. A pilot light indicates when the ion exchange resin is expended
and the container is then exchanged for a new or regenerated container.
The resin can then be regenerated by the manufacturer or installer for
reuse.
2.2.2 Treatment System 6
System 6 (Figure 3d) is a granular activited carbon filter similar to
System 4. This unit attaches directly to the faucet and a button on
the faucet attachment activates the unit. A built in tap on the unit
is used to supply the product water. This system uses water pressure
to function and provides water on demand. It sits on the sinktop and
is easily removable.
2.3 Water Source III
Water Source III is a bedrock well which supplies a single family home.
The treatment unit was installed on this well later than the other units
due to difficulty in obtaining the unit.
2.3.1 Treatment System 7
This treatment unit is an activited alumina system. The 26" high cylinder
is installed in a kitchen cabinet under the sink (Figure 4). A cold water
inlet and a tap rrounted on the sink are the only plumbing connections
necessary.
This system uses existing water pressure and does not require electricity.
When the media has been expended, the cylinder must be replaced. The
spent media can then be regenerated for future reuse.
3.0 MONITORING RESUS1S
The units described in the preceeding sections have been monitored since
their installation. Samples were taken through the month of October.
However, due to reductions in laboratory personnel, samples taken after
September 27, 1981 have not been analyzed. When this data beccxnes avail-
able, an addendum to this report will be prepared.
The sampling procedure consisted of running about two quarts of water
(measured by filling and emptying the sample container two times) then
collecting a one quart sample. This sample was preserved after collec-
tion by adding 1.5 ml of nitric acid. This procedure was used to
obtain samples from all of the treatment systems except the reverse
osmosis and fractional distillation units. Because of the sampling
location in the R.O. system, a smaller quantity of water was collected.
The treated water in the fractional distillation system was collected
in a bottle, so this product water needed only to be collected and not
run through a faucet. All samples were sent to EPA's Drinking Water
Research Division Laboratory in Cincinnati, Ohio for analysis using
EPA approved methodology ( atomic absorption with a graphite furnance).
-------
-5-
The results of these analyses are presented graphically. Each water
source and the system or systems installed on it is shown on a separate
graph. Arsenic analyses for the raw water (untreated) and the treated
water are indicated by the symbols listed on the graphs. The maximum
contaminant level (MCL) allowed in public water supplies (.05 ng/1 of
arsenic) is also indicated on the graphs.
3.1 Water Source I
As shewn on Graph If the concentraions of arsenic in the raw water from
this well varied from .135 mg/1 to .240 mg/1 (average value .180 mg/1).
System 1 is a R.O. membrane plus an activated alumina cartridge. The
R.O. unit alone, sucessfully removed about 40% of the arsenic frcro the
water. This does not reduce the arsenic concentration to below the MCL.
Because the manufacturer estimated a 40-50% removal capacity, he provided
an additional activated alumina cartridge for the system. This total
system (R.O. and A.A.) constantly achieved removal to or below the
laboratory detection limit of .005 mg/1, which is well below the MCL.
System 2, the reverse osmosis membrane plus an ion exchange cartridge
(R.O. + I.X.), began to remove arsenic to the detection limit after
several weeks.
System 3, the fractional distillation unit (F.D.) removed arsenic to be-
lcw the detection limit at each analysis.
System 4, the activated carbon/silver unit (A.C.), removed some arsenic
but the product water arsenic concentration was not consistantly below
the MCL. Ihe high reading is suggested to reproesent sloughing off of
arsenic from the carbon.
3.2 Water Source II
As shown on Graph II, the concentrations of arsenic in the raw water from
this well varied from .162 mg/1 to .245 mg/1 (average value .215 mg/1).
System 5, an ion exchange unit (I.X.), generally removed arsenic to
about the MCL. Hcwever, one sanple was slightly above the MCL.
System 6, a granular activated carbon system (GAC) removed some of the
arsenic but failed to lower the concentration of arsenic to below the MCL
at any time.
Product water from the softener was also monitored, and this unit
proved ineffective in removing arsenic.
3.3 Water Source III
As shown on Graph III, the concentration of arsenic in the raw water from
this well varied from .035 mg/1 to .335 mg/1 (average value .176 mg/1).
System 7, an activated alumina unit (AA) consistantly removed the arsenic
to belcw the detection limit of .005 mg/1.
-------
GRAPH I
-------
GRAPH II
« Rm WATER
O SYSTEM 5- SOFTENER
X SYSTEM 5-1.X.
O SYSTEM 6-G.A.C.
• 15 So *5 fro . 90 l<*> iao \yS go Ifc* 1*0
tu(*£ CJtay*)
-------
-o-
GRAPH III
WCL
(,O >5 <10 105
4-IMkS fAt
-------
-9-
3.4 Other Monitoring Programs
EPA has been monitoring similar types of systems in Alaska. Graphs
IV and V shew the results from nearly 20 months of monitoring. The re-
sults obtained from these studies show removal capabilities similar to
those obtained during this study. The raw water used in the Alaska
studies had higher initial arsenic concentrations.
4.0 CONCLUSIONS
During the duration of this monitoring program, several of the treatment
systems have consistently removed arsenic to below the MCL (.05 mg/1) and
even to or below the detection limit of .005 mg/1. These systems are:
0 Reverse osrtosis with an activated alumina cartridge
0 Reverse osmosis with an ion exchange cartridge (after some initial
high levels)
0 Fractional distillation
° Activated alumina
The ion exchange unit achieved arsenic removal to below the MCL except
for one test, while the reverse osmosis system achieved about 50%
removal of arsenic. Both granular activated carbon units failed to
consistently remove arsenic to below the MCL.
The results obtained from this monitoring program represent the removal
capabilities of these systems over a period of five months. Prediction
of future removal capabilities cannot be made from these data. Differ-
ent removal results may be obtained from raw water of different chemis-
try and arsenic concentrations.
5.0 RECOf-iMENIftTIQNS.
If a homeowner is contemplating the purchase of a treatment system, he
should take into consideration the raw water arsenic concentration of
his well, results from monitoring programs such as this, and the cost
of purchasing and maintaining a system. If any system is installed
for home use, a prudent monitoring program should be requested from
the manufacturer, if one is not already specified by the manufacturer.
-------
-10-
A
*
i
GRAPH' IV
ARSENIC REMOVAL SYSTEM
8UPSON HOUSC ALASKA
I
e
o
AO -
£Kt -
£ O-ot
4
«»«/ -
/tmn /p*y«)
LEGEND H RAtf CUTER 6 ftO iFFLUEMT X K EFFLUENT + AA EFFLUENT
GRAPH V
ARSENIC REMOVAL SYSTEM
C^CT KXfSE AUSKA
e,#o/.
itgemo w ftttreora
oro Bfuotr
XKBfUOfT
4 AA EFTLLCNT
-------
APPENDIX A
Bon-Del
c/o Kenneth Corrigan
1712 Gordon Avenue
Lansing, Michingan 48910
- granular activated carbon
Culligan USA
One Culligan Parkway
Northbrook, Illinios 60062
- R.O.
- R.O. with ion-exchange cartridge
- R.O. with activated alumina cartridge
Robert Lessor
Hillside Terrace
Merrimack, New Hampshire 03054
- fractional distillation
Lindsay Water Conditioning
Main Street
Harpstead, New Hampshire 03841
- ion exchange
Multi-Pure Drinking Water Systems
12926 Saticqy Street
North Hollywood, California 91605
- activated carbon/silver
Water Treatment Engineers
6455 E. Vernon
Scottsdale, Arizona 85257
- activated alumina
-------
I RAW WATER |
i —r
I SEDIMENT |
"I FILTER j"
i r
IRQ UNIT|
"I UN IT 1"
waIte
i r
I PRESSURE |
"I TANK |"
I ACTIVATED |
IALUMINA |
'1 CARTRIDGE
i r
I RELIEF|
"I VALVE I
I
I
| WASTE
I
L
a) Schematic Diagram
I CARBON
I FILTER
TAP
1
b) Sketch of Installation
1. Sediment filter
2. Reverse Osmosis Membrane
3. Pressure Reservoir
4. Activated Alumina Cartridge
5. Pressure Relief Valve
6. Carbon Filter
7. Fauoet
FIGURE I
-------
i r i r i r i r Hon r i r
I RAW WATER 1 | SEDIMENT | |R0 UNIT| | PRESSURE | | EXCHANGE | | RELIEF |
I | [FILTER 1 |UNIT | iTANK 1 1 CARTRIDGE| | VALVE 1
waI
TE J WKSTE
T
I CARBON | | TAP
[FILTER | |
a) Schematic Diagram
iSu
1
\
b) Sketch of Installation
1. Sediment filter
2. Reverse Osmosis Membrane
3. Pressure Reservoir
4. Ion Exchange Cartridge
5. Pressure Relief Valve
6. Carbon Filter
7. Faucet
FIGURE 2
-------
1 T | FRACTIONAL [ 1 T
I RAW WATER t I DISTILLATION j j COLLECTION j
4a) I I I UNIT | | BOTTLE |
j
I
I
I
WASTE
i r i r
I RAW WATER I I AC UNIT I I TAP I
J 1 J L J I
i r i r i r i r
I RAW WATER I I WATER I I ION EXCHANGE | | TAP I
j j_ | SOFTENER I I UNIT j_ J 1_
I
| RAW WATER
T
T
4d)
WATER
SOFTENER
I GAC UNIT |
'I I"
TAP
FIGURE 3
-------
i r i r i r
I RAW WATER I I ACTIVATED | | TAP |
| | | ALUMINA | | |
a) Schematic Diagram
1
b) Sketch of Installation
1. Activated Alumina Cylinder
2. Faucet
FIGURE 4
------- |