In addition to the rules set forth in Chapters 62-524 and
62-532, F.A.C., the requirements of this section apply to public water system
wells.
(5) Control of Copper Pipe Corrosion and
Black Water. Applicants for a construction permit to connect a new or altered
well to a community water system, except those applicants who have submitted a
complete application to the Department before August 28, 2003, shall include in
the preliminary design report or design data accompanying their permit
application the results of measurements for alkalinity, dissolved iron,
dissolved oxygen, pH, total sulfide, and turbidity in a minimum of one sample
of raw water from the new or altered well. These measurements may be performed
by any authorized representative of the supplier of water or applicant; but
field measurements for dissolved oxygen, pH, and turbidity shall be performed
following the appropriate procedures in the Department of Environmental
Protection Standard Operating Procedures for Field Activities, DEP-SOP-001/01,
as incorporated into Rule
62-160.800, F.A.C., and all
other measurements shall be performed using an appropriate method referenced in
subsection
62-550.550(1),
F.A.C., or in
Standard Methods for the Examination of Water and
Wastewater as adopted in Rule
62-555.335, F.A.C. If the result
for total sulfide equals or exceeds 0.3 mg/L, the applicant shall do the
following:
(a) Provide aeration or other
appropriate treatment of the water from the new or altered well to remove total
sulfide as necessary. Recommended types of aeration treatment for different
water quality ranges are listed in the table below, which is incorporated
herein as guidance and not as a requirement. Direct chlorination shall not be
used to remove (i.e., oxidize) 0.3 mg/L or more of total sulfide unless the
elemental sulfur formed during chlorination is removed.
POTENTIAL FOR IMPACTS WITHOUT TOTAL SULFIDE
REMOVAL
|
WATER QUALITY RANGES
|
POTENTIAL WATER TREATMENT
|
Low
|
Total Sulfide < 0.3 mg/L
Dissolved Iron < 0.1 mg/L1
|
Direct Chlorination2
|
Moderate
|
0.3 mg/L Total Sulfide 0.6 mg/L @ pH 7.2
or
0.3 mg/L Total Sulfide 0.6 mg/L @ pH > 7.2
|
Conventional Aeration3 (maximum removal efficiency
40-50%)
or
Conventional Aeration with pH Adjustment4, 5 (maximum
removal efficiency 40-50%)
|
Significant
|
0.6 mg/L < Total Sulfide 3.0 mg/L @ pH 7.2
or
0.6 mg/L < Total Sulfide 3.0 mg/L @ pH >
7.2
|
Forced Draft Aeration3 (maximum removal efficiency
90%)
or
Forced Draft Aeration with pH Adjustment4, 5 (maximum
removal efficiency 90%)
|
Very Significant
|
Total Sulfide > 3.0 mg/L
|
Packed Tower Aeration with pH Adjustment4, 5 (maximum
removal efficiency > 90%)
|
1. High iron content raises concern if chlorination
alone is used and significant dissolved oxygen exists in the source water.
Filtration may be required to remove particulate iron prior to water
distribution.
|
2. Direct chlorination of sulfide in water in the pH
range normally found in potable sources produces elemental sulfur and increased
turbidity. Finished-water turbidity should not be more than two nephelometric
turbidity units greater than raw-water turbidity.
|
3. Increased dissolved oxygen entrained during
aeration may increase corrosivity.
|
4. Reduction of alkalinity during pH adjustment and
high dissolved oxygen entrained during aeration may increase corrosivity.
Corrosion control treatment such as pH adjustment, alkalinity recovery, or use
of inhibitors may be required.
|
5. High alkalinity will make pH adjustment more
costly, and use of other treatment may be in order. Treatment that preserves
the natural alkalinity of the source water may enhance the stability of
finished water.
|
(b)
Provide in the preliminary design report or design data accompanying the
applicant's permit application a water quality and treatment evaluation
affirmatively demonstrating that the secondary maximum contaminant levels for
color and odor will not be exceeded in the water supplier's drinking water
distribution system or in water customers' potable water
systems.
(6) Disinfection
of Wells and Bacteriological Surveys and Evaluations of Wells. Wells shall be
disinfected to inactivate any microbiological contaminant that may have been
introduced into the wells during construction, repair, or maintenance and to
allow the true microbiological character of well water to be determined through
a bacteriological survey.
(a) Before new or
altered wells, wells out of operation for more than six months, wells in which
new pumping equipment has been installed, and wells taken out of operation for
maintenance that might have contaminated the well are placed into, or returned
to, operation, they shall be disinfected in accordance with Sections 1. through
4. and Section 5.2 of American Water Works Association (AWWA) Standard C654 as
incorporated into Rule
62-555.330, F.A.C. In Section
5.2 of the aforementioned AWWA standard, references to Section 5.1 shall be
interpreted to mean paragraph
62-555.315(6)(b) or
(c), F.A.C., as appropriate. This paragraph
does not apply to, and disinfection is not required for, wells that officially
have been determined to be under the direct influence of surface water per
subsection
62-550.517(2),
F.A.C., and subparagraph
62-550.817(2)(a)
1., F.A.C., and that are pumping to treatment plants with filtration and
disinfection facilities meeting all applicable requirements in Rule
62-550.817, F.A.C.
(b) Following disinfection of a new or
altered well or a well that has been out of operation for more than six months,
a bacteriological survey of the well shall be conducted as set forth in
subparagraphs 1. through 3., below, unless the well is already considered
microbially contaminated or susceptible to microbial contamination per
subparagraph 2., below, or paragraph (f), below. The total residual chlorine
measurements required under subparagraph 1., may be performed by any authorized
representative of the supplier of water or person constructing or altering the
well but shall be performed following the appropriate procedures in the
Department of Environmental Protection Standard Operating Procedures for Field
Activities, DEP-SOP-001/01 as incorporated into Rule
62-160.800, F.A.C. The total
coliform or
E. coli analyses required under subparagraph 1.
shall be performed by a laboratory of the Department of Health (DOH) or a
laboratory certified by the DOH to perform bacteriological analyses of drinking
water and shall be performed using an appropriate method referenced in
subsection
62-550.550(1),
F.A.C.
1. A total of at least 20 samples -
each taken on a separate but consecutive workday and taken at least six hours
apart from the other samples - shall be collected after first pumping the well
to waste to remove all residual chlorine and then pumping the well to waste at
a rate approximately equal to that of the permanent well pump for at least 15
minutes before each sample is collected, and the samples shall be analyzed for
the presence of total residual chlorine, total coliform, and E.
coli. Upon a showing by the supplier of water, or a determination by
the Department, that historical records or other circumstances warrant it, the
Department shall allow the required number of samples or the sample collection
interval to be modified. Under no circumstances shall the Department allow
fewer than ten samples to be collected, and under no circumstances shall the
Department allow more than two samples to be collected per day. If the
Department allows collection of two samples per day, the samples shall be
collected at least six hours apart, and the well shall be pumped to waste for
at least 15 minutes before each sample is collected.
2. If any sample shows the presence of free
or combined chlorine, the sample shall be considered invalid. If any sample
shows the presence of
E. coli, the well shall be considered
microbially contaminated unless the Department invalidates the sample or the
supplier of water determines and eliminates the source of the
E.
coli, in which case the well shall be redisinfected in accordance with
paragraph (a), above, and resampled in accordance with subparagraph 1., above.
If more than ten percent of the total number of samples collected show the
presence of total coliform or if either of the last two samples collected shows
the presence of total coliform, the well shall be redisinfected as necessary in
accordance with paragraph (a), above, and resampled in accordance with
subparagraph 1. above or shall be considered susceptible to microbial
contamination. If a well is considered microbially contaminated or susceptible
to microbial contamination, the supplier of water shall provide treatment that
reliably achieves at least four-log inactivation or removal of viruses in
accordance with paragraph
62-555.320(12)(b),
F.A.C. Additionally, the supplier of water shall conduct physical
characteristics monitoring in accordance with subsection
62-550.517(2),
F.A.C., when notified in writing by the Department to do so.
3. Bacteriological test results shall be
considered unacceptable if the tests were completed more than 60 days before
the Department received the results.
(c) Following disinfection of a well in which
new pumping equipment has been installed or a well taken out of operation for
maintenance that might have contaminated the well, a bacteriological evaluation
of the well shall be conducted as set forth in subparagraphs 1. through 3.,
below, unless the well is already considered microbially contaminated or
susceptible to microbial contamination per subparagraph
62-555.315(6)(b)
2., or paragraph (f), below. The total residual chlorine measurements required
under subparagraph 1., may be performed by any authorized representative of the
supplier of water but shall be performed following the appropriate procedures
in the Department of Environmental Protection Standard Operating Procedures for
Field Activities, DEP-SOP-001/01 as incorporated into Rule
62-160.800, F.A.C. The total
coliform analyses required under subparagraph 1., shall be performed by a
laboratory of the Department of Health (DOH) or a laboratory certified by the
DOH to perform bacteriological analyses of drinking water and shall be
performed using an appropriate method referenced in subsection
62-550.550(1),
F.A.C.
1. After pumping the well to waste for
at least 15 minutes with zero chlorine residual, a total of at least two
samples - each taken on a separate day and taken at least six hours apart from
the other sample(s) - shall be collected, and the samples shall be analyzed for
the presence of total residual chlorine and total coliform.
2. If any sample shows the presence of free
or combined chlorine, the sample shall be considered invalid. If any sample
shows the presence of total coliform, the well shall be redisinfected as
necessary in accordance with paragraph (a), above, and resampled in accordance
with subparagraph 1., above, until two consecutive samples show the absence of
total coliform.
3. Bacteriological
test results shall be considered unacceptable if the tests were completed more
than 60 days before the Department received the results.
(d) Except as allowed under paragraph (e),
below, and except as allowed under any special construction permit condition
established in accordance with paragraph
62-555.533(2)(f),
F.A.C., no disinfected well shall be placed into, or returned to, operation
until a bacteriological survey or evaluation has been completed if required by
paragraph (b) or (c), above, results of the survey or evaluation have been
submitted to the appropriate Department of Environmental Protection (DEP)
District Office or Approved County Health Department (ACHD) if a survey or
evaluation is required, and said DEP District Office or ACHD has approved the
well for operation.
(e) When
installing new well pumping equipment for which a public water system
construction permit is not required per subsection
62-555.520(1),
F.A.C., or when taking a well out of operation for maintenance that might
contaminate the well, the well may be returned to operation without the
Department's approval after completion of disinfection and after satisfactory
completion of a bacteriological evaluation if such an evaluation is required
under paragraph (c), above. If a bacteriological evaluation is required, the
results of the evaluation shall be submitted to the appropriate Department of
Environmental Protection District Office or Approved County Health Department
along with the next monthly operation report(s) required under paragraph
62-555.350(12)(b),
F.A.C., or if no monthly operation report is required under paragraph
62-555.350(12)(b),
F.A.C., within ten days after the end of the month during which the evaluation
was completed.
(f) All public water
systems using ground water not under the direct influence of surface water are
required by subsections
62-550.518(2), (3) and
(10), F.A.C., to periodically sample the raw
ground water for microbiological contamination. In the event a raw water sample
is positive for
E. coli, the relevant well(s) shall be
considered microbially contaminated unless the Department invalidates the
sample or the supplier of water determines and eliminates the source of the
E. coli, after which the supplier of water shall disinfect and
bacteriologically survey the well(s) in accordance with paragraphs (a) and (b),
above. If a raw water sample is positive for total coliform bacteria and if the
relevant well(s) are not already considered microbially contaminated or
susceptible to microbial contamination, the supplier of water shall disinfect
and bacteriologically survey the well(s) in accordance with paragraphs (a) and
(b) above when notified in writing by the Department to do
so.