This document discusses the key considerations for a utility converting from groundwater to surface water sources. It outlines the public perception challenges, increased costs associated with capital investments, operation and monitoring, and the need for greater treatment and system operation expertise. Specifically, surface water requires more sophisticated treatment like chloramination, extensive water quality monitoring, and management of water age and storage to properly maintain water quality standards.

1. SouthWest
Water Company
What a utility needs
to consider when
converting a system
to surface water.
Presented by: JR Reavis

2. JR Reavis
SouthWest Water Company

3. PUBLIC OPINION
2

4. WHAT PEOPLE THINK WHEN YOU TELL
THEM THEY ARE DRINKING TREATED
SURFACE (LAKE OR RIVER WATER)
3

5. Public Opinion
● Most people don’t understand why they are being forced
don t
to convert to surface water
Ground subsidence, aquifer depletion or cost
● Most customers can’t believe it could cost more
If you’re not one that is being converted why should you
’ t th t i b i t d h h ld
pay
● Most people assume that ground water is pristine and all
surface water is of low quality and less safe to drink
All drinking water, including bottled water, may reasonably
be expected to contain at least small amounts of some
contaminants
Surface water (source water) does have a higher potential
for contaminants and th t i why the monitoring and
f t i t d that is h th it i d
treatment standards are higher for surface water treatment
The presence of contaminants does not necessarily indicate
that the water poses a health risk, that is why the EPA and
TCEQ set limits on contaminants that pose a health risk
Fact! Both are safe when properly treated, both are
monitored to ensure public safety, both must meet rigorous
drinking water standards
4

6. WHAT NEEDS TO BE CONSIDERED?
● Why convert to surface water?
● Is there really a difference in water characteristics?
● Cost
Capital investments
General operation
● Increased monitoring to maintain water quality
● Increased need for treatment expertise
● Changes to system operation
New treatment systems and system upgrades
d d
Maintenance of standby well systems
Staffing and licensing requirement
● Water Quality Issues
Why chloramine disinfection?
Water age management
Water storage
System flushing
Disinfection schemes
Higher formation potential for disinfection by-product and other
by-
regulated contaminants
● Relationship with your water wholesaler
5

7. WHY CONVERT TO SURFACE WATER?
● Your utility may be required to participated in
a ground water reduction program (Subsidence
or Conservation Districts: Harris Galveston,
Fort Bend County, Lone Star, etc…)
● Demand has outstripped available ground
water supply
● Ground water may contain regulated
contaminants that are difficult to treat or
would be more costly to treat than using an
alternate surface water source (Arsenic,
Fluoride, Radon, etc…)
● It’ cheaper to b
It’s he pe buy water from a wholesaler
te f om hole le
than it is to rehab or develop new ground
water sources
6

8. IN THE HOUSTON AREA SUBSIDENCE IS
THE PREDOMINANT DRIVING FORCE
BEHIND THE CONVERSION
7

9. HOUSTON AREA SUBSIDENCE MAP
http://pubs.usgs.gov/ha/ha730/ch_e/gif/E064.GIF
8

10. GROUNDWATER LEVELS IN THE HOUSTON
AREA FROM 1931 TO 1970
9

11. GENERAL
DIFFERENCES
SURFACE vs. GROUND
WATER
10

12. Ground Water Surface Water
• Generally higher levels of • Generally higher level or
inorganics, low or no organics organics, inorganics less of an
• Hydrogen sulfate iron,
sulfate, iron issue
manganese and other • Organics can cause taste, odor
constituents can cause taste, and color issues
odor and color problems • Higher DBP formation potential
• Low DBP formation potential • Generally requires more
• Historically most utilities use
i i ll ili i sophisticated di i f
hi i d disinfection
i
free chlorine to disinfect scheme, chloramine disinfection
(simple disinfection scheme) is commonly used
• Water age is not an less of an • Water age is a big consideration
issue because most ground
ssue ost g ou d (sto age a d us
(storage and flushing are very
ga e e y
water lacks organics to exert a important)
demand on chlorine • System wide management is
• System wide water age required to maintain water
management is less of an issue quality
because water does not • More complicated treatment
degrade in the system as easily needed (can change frequently
• Water chemistry is relatively for multitude of reasons)
simple, or at least it doesn’t • More complicated monitoring
change frequently requirements, higher level of
• Monitoring requirements are
M it i i t operator skills required
t kill i d
relatively simple, less technical • Time demand on the operator is
skills required to operate much higher
• Operator time requirements are
relatively low
y
11

13. COSTS
Capital &
GENERAL OPERATING
12

14. CAPITAL COSTS
● New treatment equipment
Installation of storage tanks, high service pumps, chemical
feed equipment, instrumentation, etc…
● Modifications to existing water storage tanks
Alternate fill & take points, monitoring equipment, mixers
● Improvements to existing chemical feed equipment
Pump replacements, metering & monitoring equipment
replacements
(SCADA?)
● Piping and valve replacements
In the facility and in the system
Installation of system interconnects, valves, PRVs and
meters
● Modifications to existing well systems
Blow offs, SCADA control, monitoring, etc… (Just to insure
reliability when needed.)
● Costs associated with capping abandoned wells
13

15. GENERAL OPERATING COSTS
● Increased operator presence
Higher degree of compliance
Higher degree of monitoring sampling
Increased distribution presence ( y
p (system flushing &
g
customer complaint response)
Higher need for technical support
Increased maintenance support for monitoring and
chemical feed equipment
● Increased costs associated with maintaining standby well
systems
● Increased chemical costs to maintain disinfectant
residuals
● Increased laboratory fees associated with a higher level
of monitoring
g
● Increased costs associated with purchasing surface
water
● Increased need for system flushing
14

16. MONITORING
15

17. INCREASED MONITORING TO
MAINTAIN WATER QUALITY
● Unless mandated by special need, ground water
facilities do not require extensive online monitoring
● Surface water plants have specific grab and online
monitoring requirements in order to maintain regulatory
compliance
● Repump stations may require online monitoring to
insure water quality
● Whether being treated or repumped, surface water
requires more extensive process monitoring to insure
water quality
● Operators will need a higher level of treatment
knowledge to deal with the more complicated treatment
issues associated with surface water
● Process monitoring is the best tool the operator has to
address problems before they become big issues
16

18. Typical chemical & sampling scheme for
a ground water system prior to
d t t i t
chloramine conversion
1 - Free chlorine sample in the plant
Sample
Cl2
GST
Distribution
Well
17

19. Typical chemical application & sampling
points when purchasing surface water
from a wholesaler with no well water
being used
g
4 - Free chlorine samples in the plant
4 - Total chlorine samples in the plant
4 – Monochloramine samples in the plant
4 – Free ammonia samples in the plant
Sample Sample Sample
Sample
NH3 Cl2
Cl2 NH3
Purchased GST
Water
(chloraminated ) Distribution
18

20. Typical chemical application & sampling
points when purchasing surface water
from a wholesaler with a well system
being used
5 - Free chlorine samples in the plant
5 - Total chlorine samples in the plant
5 – Monochloramine samples in the plant
5 – Free ammonia samples in the plant
Sample Sample
Sample Cl2
Cl2 NH3
NH3
GST
Distribution
Well
Sample Sample
NH3
Cl2
Purchased
Water
(chloraminated )
19

21. THINGS TO REMEMBER ABOUT
ONLINE MONITORING EQUIPMENT
● When used properly online monitoring
instruments are great diagnostic tools
● Online monitoring equipment is only as good
as the maintenance performed on them
● Caution should be used when online
monitoring equipment is used to control
chemical feed equipment
Online equipment fails and often generate false data
Total reliance upon online monitoring equipment
l l l
without operator input will result in catastrophic
treatment failure
Online monitoring equipment can not replace
operator knowledge
A good operator always assumes the online
equipment is wrong Verify! Verify! Verify!
wrong.
20

22. TREATMENT
EXPERISE
21

23. INCREASED NEED FOR TREATMENT
EXPERTISE
Ground Water Surface Water
● Most ground water operators ● Because of the organic nature
have long term familiarity with of surface water, quality
the ground water operation but changes can occur frequently in
lack familiarity with surface a surface water system
water treatment issues making ● It is often hard to diagnose the
technical support a necessity problem because of the
● Few changes occur from day-to- complexity of the source water
day in ground water quality (What worked the previously
● Ground water lacks the organic may not work this time)
constituents that create ● Treatment needs change with
constantly changing treatment the seasons or weather
needs conditions
● Once a successful treatment ● The distribution system is more
scheme is determined it is biologically active and needs to
seldom changed be addressed accordingly
● Problems associated with DBP ● DBP formation potential is more
formation are less likely with likely due to the presence of
water that contains little or no organics in the source water
organic material ● More extensive regulatory
compliance requirements than
those required for ground water
Diagnosis and reaction to treatment issues quickly
are crucial for systems using surface water!
22

24. SYSTEM OPERATIONS
23

25. CHANGES TO SYSTEM OPERATION
● New treatment systems and system upgrades
Operating a surface water system will require the
addition of numerous new chemical feed systems:
coagulant, polymers, ammonia, pH adjustment
systems, oxidants (KMnO4, chlorine dioxide, ozone),
fluoride, etc…
Higher number of feed systems will require greater
operator knowledge and skills in order to make chemical
dosages changes and perform monitoring tests
Higher importance needs to be placed on equipment
maintenance
– E i
Equipment redundancy i a must
d d is
– The system should have a managed maintenance system
to track routine, corrective and emergency repairs, as well
as manage parts inventory
– B d
Budgeting for equipment replacement and reconditioning
i f i l d di i i
is even more important due to the number of equipment
items and the importance that each item has in the
performance of the plant
– Maintaining monitoring equipment will require more time
and expertise on the maintenance staff
24

26. Possible increases in time spent by
operators taking additional samples
*Surface
Old Well *Surface Water Water with
Systems Only Well Water
Supplement
S l t
Free Chlorine 2 @ 30 sec each 4 @ 30 sec each 5 @ 30 sec each
5 @ 1 min 30
Total Chlorine na 4 @ 1 min 30 sec each
sec each
Monochloramine/
na 4 @ 12 min each 5 @ 12 min each
Free Ammonia
Sample
2 @ 5 minutes 4 @ 5 min each 5 @ 5 min each
Collection Time
Sample Reruns 1 @ 30 sec each 2 @ 15 min each 2 @ 15 min each
Total Time ~ 1 Hours ~ 2 Hours
~ 12 minutes
Required 46 minutes 5 minutes
*Although the operator will not always be required to sample all location, if
problems exist the operator will be doing at least the number of samples listed
above. This estimate does not include time spent checking chemical feed
systems.
25

27. Possible increases in time & money spent
by chlorine and maintenance technicians
Old Well Surface Water Only or Surface Water
Systems with Well Water Supplement
(None) (Two or more)
On-
On-line Chlorine
Generally done Most systems will have 1 on both the
Analyzer
by grab sample incoming surface line and the outgoing line
(None) (Possibly two or more)
Monochloramine
It wasn’t Most systems will have 1 on both the
/ Free Ammonia
necessary incoming surface line and the outgoing line
Inspections and calibrations are part of
Surface Flow
(None) routine maintenance (an expense to the
Meter/PRVs
district)
Chemical (Possibly as many as six)
(One)
metering Depending on configuration, 3 units for each
Chlorinator
devises ammonia and chlorine
Each additional piece of equipment will require additional time on the part of the
maintenance staff. Example: Each of the monochloramine/ammonia analyzers
could require as much as 3-5 hours a week for the operator/maintenance staff.
3-
In addition, $3,000 to $4,500 annually should be budgeted for its use (reagents,
parts, required routine maintenance and possible replacement).
26

28. Possible increases in time and money
spent in the distribution system
Old Well Surface Water Only or Surface Water
Systems with Well Water Supplement
(required Based on need, it is possible that the
minimum) system could require as much as 2 to 3
Flushing
Dead ends times as much flushing to maintain water
once/month quality.
(
(most p
probably
y THM, HAA5, HPC, nitrite, nitrate and
Monitoring
M i i none) ammonia samples will need to run on the
i l ill d h
samples for incoming water, at the high service pumps
It wasn’t
operational and in the system. The frequency will range
necessary
purposes from weekly to monthly depending on
conditions within the system.
(none) The only way monitoring samples will be of
use is if they are easily tracked and
Monitoring Generally only available when needed. It is also one of the
sample compliance only tools the client has to address issues
y
recordkeeping
dk i samples are
l with water quality coming from the
tracked wholesale supplier.
Flushing is a real cost that is realized by the district. More importantly
monitoring samples necessary to operate the system properly will be additional
expenses that the district will incur to insure water quality.
Don’t forget to budget for maintaining
standby well systems! 27

29. CHANGES TO SYSTEM OPERATION
● Maintenance of standby well systems
A system seldom used could be more expensive to
maintain than one that is used on a routine basis
Exercising on a routine basis is a must to insure
reliability
● Staffing and licensing requirement
A more complicated system requires a higher degree
of skill on the part of the operator
Scarcity and competition f skilled operators will
S it d titi for kill d t ill
drive the cost of operation up
You can’t expect to staff a repump station or surface
water plant the same as a ground water system
t l t th d t t
considering the added in plant and system operating
requirements
28

30. WATER QUALITY
29

31. WATER AGE MANAGEMENT ISSUES
● Water t
W t storage – a ground water system may not be
d t t tb
configured properly to manage water age in the storage
tanks because historically most storage facilities were
designed to:
Equalized demands
Reduce pressure issues in the system
Provide a reserve for fire fighting or other emergencies
● Ground water operating strategy of “keep it full at all
times in case of emergency” is no longer a wise
operating strategy
Deep cycling storage tanks becomes very important
It is possible that existing storage tanks will need
modifications
Baffles, mixers, tank inlets and outlets changed
Elevated storage tanks can be a big concern and need to
be managed to p
g prevent aged water p
g problems
30

32. WATER AGE MANAGEMENT ISSUES
● System flushing – Dead end flushing becomes very
important to system water quality
● Water containing organics (surface water) will
experience chlorine decay more rapidly than systems
p y p y y
using ground water
● Customer complaints need to be tracked to determine
where problems are occurring (don’t assume dead ends
are the only problem areas)
● Tracking water quality parameters such as taste, odor,
HPCs, chlorine residual, nitrite, nitrates and free
ammonia are very important
● Auto flushers will help control low chlorine residuals,
taste and odor complaints and to reduce operator time
in the field
● Maintenance of the complete system is more important
Treatment problems don’t stop at the facility fence
Treatment problems are not self correcting
31

33. BASIC GROUND WATER OPERATION
Well
Elevated
Storage Cl2
Well
Pump
Ground
Storage
Well
Elevated
Storage
Storage
Cl2
Cl2
Cl2
Pump Pump
Ground
Storage
32

34. BASIC SURFACE WATER OPERATION
WHOLESALER TO END USER
Flocculation
Bar Sedimentation Filters
Rapid
Pre-
Pre- Screen Mix
RAW Sedimentation
S di t ti
SOURCE
Chemical Bld
Initial treatment
1st Cl2 - 2nd NH3
Booster treatment Chemical Feed
NH3 1st NH3 - 2nd Cl2
Cl2 Repump Pump
Storage Storage
Cl2
NH3 NH3 Cl2
NH3 Cl2
Repump
Storage
33

35. COMBINE THE TWO AND IT GETS
COMPLICATED Well
Flocculation
Elevated Bar Sedimentation Filters
Storage Rapid
RAW
Pre-
Pre- Screen Cl2Mix
Sedimentation
S di t ti
SOURCE Well
Pump
Ground
Storage
Well Chemical Bld
Initial treatment
Elevated 1st Cl2 - 2nd NH3
Storage
Storage
Cl2
Booster treatment Chemical Feed Cl2
Cl2
NH3 1st NH3 - 2nd Cl2
Cl2 Repump Pump
Storage Storage
Pump Pump
Ground
Cl2
Storage 3
NH NH3 Cl2
NH3 Cl2
Repump
Storage
34

36. TREATMENT AND
DISINFECTION
35

37. Chloramination Breakpoint Curve
Understanding
Breakpoint
Chemistry is
Ch i t i
Critical!
Chlorine
destroyed by
reducing
compounds Some
Trichloramines
9:1, Cl2:NH3-N
,
36

38. WHY CHLORAMINE DISINFECTION?
● C ’t hold a disinfectant residual i th distribution
Can’t h ld di i f t t id l in the di t ib ti
system
Free chlorine is a stronger disinfectant that quickly reacts
with anything that will oxidize
THMs (a regulated disinfection by-product) rapidly form in the
by-
presence of free chlorine and organics
In the presence of organics the free chlorine disinfectant
residual is quickly consumed
Chloramines are a weaker disinfectant but more stable than
chlorine
Weaker, Less reactive disinfectant, that is why is it not used as
the primary disinfectant in water treatment, but when used in
conjunction with a stronger disinfectant it is very effective
j g y
Provides a higher residual in the distribution system
● In some cases a utility may want to convert to
chloramine disinfection even though they are not
converting to surface water
Utilities that frequently use an emergency interconnect with
a neighboring system that does utilizes chloramine
disinfection in their distribution system
You will have problems in the distribution if you try to
operate a system using both chlorine and chloramines
37

39. Chlorine/Chloramine Interaction in
the Distribution System
Transition
Zone
Fewer Very Fewer
Customer Unhappy Customer
From Complaints Customers Complaints Well Water
Wholesaler
Good Low Good or System
with Chlorine Chlorine Chlorine us g ee
using Free
Chloramines
Chl i Residuals Residuals Residuals Chlorine
Bad Taste &
Odor Issues
High Levels
of DBPs
● You can’t run a system with chlorine and chloramines
simultaneously because it creates a transition zone with very
unhappy customers.
customers.
● Depending on system pressures, the transition zone can move.
move.
You can tell this by monitoring customer complaints.
complaints.
38

40. Chlorine Reaction with Water
Chl i R ti ith W t
Cl2 + H 2O HOCl + HCl
H
H O H
Cl
Cl
+ O Cl + Cl
H
Chlorine + Water Hypochlorous
Acid
+ Hydrochloric
Acid
39

41. Monochloramine Formation
HOCl + NH3 NH2Cl + H 2O
H H
O H N H
Cl + H
N H
Cl + O
H H
Hypochlorous
hl
Acid + Ammonia Monochloramine + Water
40

42. DISINFECTION SCHEMES
● I order to maintain disinfection residuals i th system
In d t i t i di i f ti id l in the t
chloramines may need to be used
● Systems using both ground water and surface water
must use the same disinfection scheme
● In order to avoid problems, systems that routinely rely
on interconnects with other systems will need to
conform to the same disinfection schemes used by the
supplier
● Chlorine chemistry becomes critical when using
chloramines
Ratios, dosages and feed rates significantly impact
formation potential of DBPs
Loss of the chlorine or ammonia feed system even for a
short period of time can become a significant compliance
problem
System monitoring, both grab and online monitoring is
monitoring
vitally important
Without adequate monitoring there is no way to avoid
water quality issues
41

43. PUBLIC HEALTH
CONCERNS
42

44. SURFACE WATER HAS A HIGHER
FORMATION POTENTIAL FOR FORMING
DISINFECTION BY-PRODUCTS (DBPs) AND
BY-
OTHER REGULATED CONTAMINANTS
● The difference, ground water lacks organics and the
difference
potential to form DBPs
DPB formation is impacted by:
Nature and quality of the source water
q y
Chlorine/chloramine concentrations
Chlorine to ammonia ratio
Temperature
Contact time (water age)
Cryptosporidium and Giardia are biological contaminants
that most ground water systems would never deal with
Both are naturally present in the intestines of most
mammals including humans, and are passed into the
environment through urban runoff or sewage disposal
system failure
43

45. NITRIFICATION
● Nitrification becomes a big issue when using
chloramines
Nitrification can impacts disinfectant residuals and
general water q
g quality
y
Many of the same issues that impact DBP formation
impact the nitrification process
Nature and quality of the source water
Chlorine/chloramine concentrations
Chlorine to ammonia ratio
Temperature
Contact time (water age)
C t t ti ( t )
Nitrification is not a self correcting issue, it can’t be
ignored
The best treatment strategy is to monitor, control
monitor
ammonia levels and reduce water age
And don’t forget, it draws the attention of the
regulators
44

46. Chloramine Formation and Decay
Controlling excess ammonia is a bigger issue than feeding
ammonia because as chloramines decay ammonia is
released to be reused, either to form more chloramines or
as a food source for nitrifying bacteria.
Source:
http://www.tawwa.org/TW07Proceedings/070412a/WaterTreatment/The%2
0Ties%20That%20Bind.pdf
45

47. The Nitrification Process
Nitrosomonas Nitrobacters
(Ammonia-
(Ammonia- (Nitrite-
(Nitrite-Oxidizing
Oxidizing Bacteria) Bacteria)
Ammonia Nitrite Nitrate
(NH3) (NO2-) (NO3-)
Optimum Conditions Influencing Factors
pH 7.5 – 8.5 Water Temperature
Temp. 25 - 30°C
30° Detention Time
Free Ammonia Excess Ammonia
Dark Environment Chloramine Concentration
Early Warning Signs Prevention and Control
Decrease in Ammonia Decrease Detention Time
Decrease in Chlorine Decrease Free Ammonia
Decrease in pH Increase Disinfection Dosage
Increase in Nitrite Ratio
Increase in HPC Breakpoint chlorinate
Establish a Flushing Program
Source: Small system Operation and Maintenance (Ken Kerry)
46

48. DEALING WITH THE
WHOLESALER
47

49. THINGS TO REMEMBER WHEN YOU BUY
WATER FROM A WHOLESALER THAT
PROVIDES TREATED SURFACE WATER
● The treatment process at the wholesaler plant is critical
If they get it wrong, it’s wrong everywhere
If they have problems, you have problems
If the wholesaler has formed DBPs, you can t remove them
DBPs can’t
easily or cost effectively
● Caution! Don’t assume that anytime there is a water
Caution!
quality problem it is the wholesalers fault because each
time water is re-chloraminated, or simply given enough
re-
time, the possibility that problems can occur increases
● Process control monitoring system entry monitoring
monitoring,
and communication with your wholesaler are the best
tools you have to insure purchased water quality
48

50. QUESTIONS:
QUESTIONS
JR Reavis
National Water Quality Director
i l Q li i
SouthWest Water Company
281-216-
281-216-3545
jrreavis@swwc.com
49