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e Determined by the permittee as high priority based on the characteristics listed in
Appendix C.

4. Low Priority Outfalls: Outfalls determined by the permittee as low priority based on the
characteristics listed below or other available information.

Outfalls were ranked into the above priority categories (except for excluded outfalls, which may be
excluded from the JDDE program) based on the following characteristics of the defined initial
catchment areas, where information was available. Where no data was available, a level value of 0 was
assigned to the outfall. To prioritize initial mapping and outfall assessment work Nashua is using
location-specific characteristics of water body impairments to focus initial work as included in
Appendix B. The level values assigned for each outfall for each of the following characteristics were
summed to reach a final score for each outfall. For the initial outfall ranking and catchment
investigations this approach will target the worst areas first.

e Previous screening results — previous screening/sampling results indicate likely sewer input
(per the criteria above for Problem Outfalls). Outfalls were given a level value of 10 if previous
screening/sampling results indicate a problem outfall and a level value of 0 if not a problem
outfall.

e Past discharge complaints and reports — Outfalls were given a level value of 3 if greater than
5 complaints /reports were filed per year, a level value of 2 for 3-4 reports filed per year, a level
value of 1 for 1-2 reports per year, and a level value of 0 for no reports per year.

e Poor receiving water quality — Catchments draining to any waterbody impaired for the

following was designated either Problem Catchments or High Priority.

© Bacteria or Pathogens

o Nitrogen

o Phosphorus

o Legacy Impairments
Outfalls were given a level value of 10 if the receiving water body was impaired, 5 if threatened,
and 0 if not impaired/not assessed.

e Density of generating sites — Generating sites are those places, including institutional,
municipal, commercial, or industrial sites, with a potential to generate pollutants that could
contribute to illicit discharges. Examples of these sites include, but are not limited to, car
dealers; car washes; gas stations; garden centers; and industrial manufacturing areas. Outfalls in
industrial sites were assigned a level value of 3, institutional/commercial sites were assigned a
level value of 2, suburban sites were assigned a level value of 1, and rural sites assigned 0.

e Age of development and infrastructure — Industrial areas greater than 40 years old and areas
where the sanitary sewer system is more than 40 years old will probably have a high illicit
discharge potential. Developments 20 years or younger will probably have a low illicit discharge
potential. Outfalls in developments greater than 40 years old were assigned a level value of 3,
developments between 20 and 40 years old were assigned a level value of 2, and developments
less than 20 years old were assigned a level value of 1.

Hic it Discharge Detection and Himination Plan 10

e Historic combined sewer systems or sewer conversion — Contributing areas that were once
serviced by a combined sewer system but have been separated and contributing areas that were
once serviced by septic systems but have been converted to sewer connections may have a high
illicit discharge potential. Separated systems were assigned a level value of 3, converted systems
were assigned a level value of 2, and areas still on septic were assigned a 1.

e Surrounding density of aging septic systems — Septic systems 30 years or older in residential
land use areas are prone to have failures and may have a high illicit discharge potential. Outfalls
with surrounding septic systems over 30 years old were assigned a level value of 3, outfalls with
surrounding septic systems between 20 and 29 years old were assigned a level value of 2, outfalls
with surrounding septic systems between 10 and 19 years old were assigned a level value of 1,

and outfalls with surrounding septic systems less than 10 years old were assigned a level value of
0.

e Discharging to an area of concern to public health — Outfalls that discharge to or in the

vicinity of any the following areas:

© Public beaches

© Recreational areas

o Drinking water supplies

o Shellfish beds
Outfalls discharging to areas of body contact or drinking water inlets were assigned a level value
of 10, outfalls discharging to areas of high recreation or boat ramp access were assigned a level
value of 5, and outfalls discharging to areas with limited or no recreation were assigned a level
value of 0.

e CCTV storm drain data — Outfalls with hard pipe connections were assigned a level value of
10, outfalls with significant structural defects were assigned a level value of 5, and outfalls with
neither were assigned a level value of 0.

The following is an initial outfall prioritization flowchart, see Appendix C for an outfall
inventory and priority ranking matrix:

Hic it Discharge Detection and Himination Plan 11

Hic it Discharge Detection and Eimination Plan

12

6 Dry Weather Outfall Screening and Sampling

Dry weather flow is a common indicator of potential dlicit connections. The MS4 Permit requires all
outfalls (excluding Problem and Excluded Outfalls) to be inspected for the presence of dry weather
flow. The Engineering Department is responsible for conducting dry weather outfall screening, starting
with High Priority outfalls, followed by Low Priority outfalls, based on the initial priority rankings
described in the previous section by the end of Year 3.

Dry weather outfall Screening and Sampling shall be completed in accordance with Part 2.3.4.7.b of the
MS4 Permit. Plans and procedures for such screening and sampling shall be incorporated into this plan.

6.1 Dry Weather Screening/ Sampling
Pro cedure

6.1.1 General Procedure

The dry weather outfall inspection and sampling procedure consists of the following general steps:

1. Identify outfall(s) to be screened/sampled based on initial outfall inventory and priority ranking
Acquire the necessary staff, mapping, and field equipment (see Table 6-1 for list of potential
field equipment)

3. Conduct the outfall inspection during dry weather:

a. Mark and photograph the outfall

b. Record the inspection information and outfall characteristics (using paper forms or
digital form using a tablet or similar device)

c. Look for and record visual /olfactory evidence of pollutants in flowing outfalls
including odor, color, turbidity, and floatable matter (suds, bubbles, excrement, toilet
paper or sanitary products). Also observe outfalls for deposits and stains, vegetation,
and damage to outfall structures.

4. If flow is observed, sample and test the flow following the procedures described in the
following sections.

5. Ifno flow 1s observed, but evidence of illicit flow exists (illicit discharges are often intermittent
or transitory), revisit the outfall during dry weather within one week of the initial observation, if
practicable, to perform a second dry weather screening and sample any observed flow. Other
techniques can be used to detect intermittent or transitory flows including conducting
inspections during evenings or weekends and using optical brighteners.

6. Input results from screening and sampling into spreadsheet/database. Include pertinent
information in the outfall /interconnection inventory and priority ranking.

7. Include all screening data in the annual report.

Hic it Discharge Detection and Himination Plan 13

6.1.2

Field Equipment

Table 6-1. Field Equipment —- Dry Weather Outfall Screening and Sampling

Equipment

Use/Notes

Clipboard

For organization of field sheets and writing surface

Field Sheets

Field sheets for both dry weather inspection and Dry weather sampling
should be available with extras

Chain of Custody Forms

To ensure proper handling of all samples

Pens/Pencils/Permanent Markers

For proper labeling

Nitrile Gloves

To protect the sampler as well as the sample from contamination

Flashlight/headlamp w/batteries

For looking in outfalls or manholes, helpful in early mornings as well

Cooler with Ice

For transporting samples to the laboratory

Digital Camera

For documenting field conditions at time of inspection

Personal Protective Equipment
(PPE)

Reflective vest, Safety glasses and boots at a minimum

GPS Receiver

For taking spatial location data

Water Quality Sonde

If needed, for sampling conductivity, temperature, pH

Water Quality Meter

Hand held meter, if available, for testing for various water quality
parameters such as ammonia, surfactants and chlorine

Test Kits Have extra kits on hand to sample more outfalls than are anticipated to be
screened in a single day
Label Tape For labeling sample containers

Sample Containers

Make sure all sample containers are clean.

Keep extra sample containers on hand at all times.

Make sure there are proper sample containers for what is being sampled
for (i.e., bacteria requires sterile containers).

Pry Bar or Pick

For opening catch basins and manholes when necessary

Sandbags For damming low flows in order to take samples
Small Mallet or Hammer Helping to free stuck manhole and catch basin covers
Utility Knife Multiple uses

Measuring Tape

Measuring distances and depth of flow

Safety Cones

Safety

Hand Sanitizer

Disinfectant/decontaminant

Zip Ties/Duct Tape

For making field repairs

Rubber Boots/Waders

For accessing shallow streams/areas

Sampling Pole/Dipper/Sampling
Cage

For accessing hard to reach outfalls and manholes

Hic it Discharge Detection and Himination Plan 14

6.1.3 Sample Collection and Analysis

If flow is present during a dry weather outfall inspection, a sample will be collected and analyzed for the
required permit parameters’. The general procedure for collection of outfall samples is as follows:

1. Fill out all sample information on sample bottles and field sheets
Put on protective gloves (nitrile /latex/other) before sampling

3. Collect sample with dipper or directly in sample containers. If possible, collect water from the
flow directly in the sample bottle. Be careful not to disturb sediments.

4. Ifusing a dipper or other device, triple rinse the device with distilled water and then in water to
be sampled (not for bacteria sampling)

5. Use test strips, test kits, and field meters (rinse similar to dipper) for most parameters (see
Table 6-1)

6. Place laboratory samples on ice for analysis of bacteria and pollutants of concern

7. Fill out chain-of-custody form for laboratory samples

8. Deliver samples to City of Nashua Wastewater Treatment Facility Laboratory or contracted
laboratory.

9. Dispose of used test strips and test kit ampules properly

10. Decontaminate all testing personnel and equipment

In the event that an outfall is submerged, either partially or completely, or inaccessible, field staff will
proceed to the first accessible upstream manhole or structure for the observation and sampling and
report the location with the screening results. Field staff will continue to the next upstream structure
until there is no longer an influence from the receiving water on the visual inspection or sampling.

Field test kits or field instrumentation are permitted for all parameters except indicator bacteria and any
pollutants of concern. Field kits need to have appropriate detection limits and ranges.

In the past, the City has contracted with the Nashua River Watershed Association for sample collection
and analysis and associated standard operating procedures.

6.2 Follow-up Ranking of Outfalls

Nashua will update and re-prioritize the initial outfall rankings based on information gathered during dry
weather screening. The rankings will be updated periodically as dry weather screening information
becomes available.

Outfalls where relevant information was found indicating sewer input to the MS4 or sampling results
indicating sewer input are highly likely to contain illicit discharges from sanitary sources.

Such outfalls will be ranked at the top of the High Priority Outfalls category for investigation. Other
outfalls may be re-ranked based on any new information from the dry weather screening.

Hic it Discharge Detection and Himination Plan 15

Board of Aldermen — 9/12/17 Page 2

Today by coincidence and | swear | didn’t see this person out but we had a meeting about another subject and
| ran into the man who was the chair of the first board of directors of the Capital Arts Center in Concord who
was responsible for raising money and getting the thing off the ground to begin with. He pointed out that the
Capital Center has transformed downtown Concord over the past couple of decades. If you know Concord and
you think about it, the Capital Center is actually not really in the middle of Main Street or middle of downtown.
It is south by a couple of blocks. Maybe three but right around the Capital Center, you’ve seen two major office
projects, residential development, plus the Red River Theater, plus a new place for Gibson’s Book Store, and a
lot of other things that have occurred right around the Capital Center. This former chair of that board believes
that this transformation was caused by the redevelopment of the Capital Arts Center. His comment was, “that
the Nashua performing arts center would bring incalculable benefits to the City of Nashua and that Main Street
at the corner of Pearl is the perfect place.” Those were his words for this opportunity.

| have heard some people are skeptical and | certainly understand that but | don’t agree with running Nashua
down. We are a great city with tremendous potential. Now we know that the Capital Center in Concord is a
success. That community is half the size of Nashua. We know that the Palace in Manchester is a success.
The Capital Center is twice the size of what we’re talking about. They’re even in Plymouth — a community that
has 1/6" or 1/7" the size of ours. The have the Flying Monkey. A successful performing arts center. The
Music Hall in Portsmouth is successful. A community % our size. Tupelo in Londonderry is successful. A
community 1/3 of our size. So this idea that Nashua just can’t work it, it’s just too skeptical, it’s got too much
doubt, it’s just never is going to work. | just don’t believe that. Why is it that Concord, Manchester, Plymouth,
Portsmouth, even Londonderry can make these performing art centers a success? Why can’t Nashua do the
same? | think there is no answer to that question because | think and | think the evidence and the facts show
that we would have an equal or a better success right on Main Street in Nashua.

| would like to take a moment to debunk some of the myths or the misunderstandings that | think have been
circulated in opposition to the idea that we can have a commercially viable successful performing arts center
on Main Street. First of all, the idea has been floated that Nashua is just blowing up debt. We’re just going
crazy. That is just going out of control. That is exactly the opposite of the truth. We are actually paying off
debt. We pay off $19 million of debt every year. Come June 30 without any further borrowing, we will have
$24 million less of debt that we did when | entered office less than 2 years ago. As | said, we’re paying off $19
million of debt.

Now the performing arts center which could cost debt of $15.5 million is not going to be built right away. We
need to raise $4 million first and it would be built over a couple of subsequent years. During that time, we will
continue to pay off $19 million of debt every year. If this were to take place in a couple of years, we would
have paid off an additional $38 million of debt for a total of $60 some million. We're going to borrow 15. Is it
possible that other projects would come forward? It’s possible but we would have to consider those on their
merits, consider our ability to pay at the time. The bonded indebtedness in this budget is down $1.5 million.
That’s out of pocket because we have reduced debt. So this idea that Nashua with its AAA bond rating is just
exploding in debt is totally and absolutely false.

The analysis | just gave you does not include the paving bonds. Now we haven’t even borrowed those yet.
We're trying to pave the streets. Those have a separate unrelated, separate non-tax, non-property tax source
of support. That being the Highway Block Grant that comes from the State of New Hampshire a small portion
of the automobile registrations that we collect downstairs. Again, none of that money has even been borrowed
yet. The projection is to borrow $30 some million over 5 years with an independent source of revenue while
again we’re paying down debt at the rate of $19 million a year.

A second myth is the Daniel Webster College auditorium could work as an alternative performing arts center.
That is not accurate. First of all if you’ve been there, and | remember Judy Carlson testified at the public
hearing — she’s been there. I’ve been there. Tim Cummings has been there. It is a very small theater with no
back of the house. It is less adequate than our high school auditoriums at North and South. It’s part of a larger
administration building. It would be very difficult or impossible — probably more expensive than here to convert
that and it doesn’t meet a fundamental goal that we’re trying to achieve which is a more economically vibrant

7 Catchment Investigations

Once stormwater outfalls with evidence of illicit discharges have been identified, various methods can be
used to trace the source of the potential discharge within the outfall catchment area. Catchment
investigation techniques include but are not limited to review of maps, historic plans, and records;
manhole observation; dry and wet weather sampling; video inspection; smoke testing; and dye testing.

Catchment Investigations shall be completed in accordance with Part 2.3.4.8 of the MS4 Permit and the
City of Nashua Written Catchment Investigation Procedures document.

7.1 MIllicit Discharge Removal

When the specific source of an illicit discharge 1s identified, Nashua will first contact the owner of the
suspect property and will exercise its authority as necessary to require tts removal. The annual report will
include the status of IDDE investigation and removal activities including the following information for
each confirmed soutce:

e The location of the discharge and its source(s)

e Adescription of the discharge

e The method of discovery

e Date of discovery

e Date of elimination, mitigation or enforcement action OR planned corrective measures and a
schedule for completing the illicit discharge removal

e Estimate of the volume of flow removed.

Hic it Discharge Detection and Himination Plan 16

8 Training

Annual IDDE training will be made available to employees involved in the IDDE program. This
training will at a minimum include information on how to identify dlicit discharges and may also include
additional training specific to the functions of particular personnel and their function within the
framework of the IDDE program. The frequency and type of training will be mcluded in the annual
report. The City of Nashua will take advantage of training opportunities offered by NHDES, the Lower
Merrimack Valley Stormwater Coalition, and the University of New Hampshire Technology Transfer
Center, including specifically the JODE Training Videos developed by the Lower Merrimack Valley
Stormwater Coalition for identifying and sampling illicit discharges. The City of Nashua will hire
consultants or contractors as needed to provide necessary trainings.

Hic it Discharge Detection and Himination Plan 17

9 Progress Re porting

The progress and success of the IDDE program will be evaluated on an annual basis. The evaluation will
be documented in the annual report and will include the following indicators of program progress:

e Number of illicit discharges identified and removed

e Number and percent of total outfall catchments served by the MS4 evaluated using the
catchment investigation procedure

e Number of dry weather outfall inspections /screenings

e Number of wet weather outfall inspections/sampling events

e All dry weather and wet weather screening and sampling results

e Estimate of the volume of sewage removed, as applicable

e Number of employees trained annually.

The success of the IDDE program will be measured by the IDDE activities completed within the
required permit timelines.

Hic it Discharge Detection and Himination Plan 18