NCS000422_Dry Weather Detection Program_20200218

Town of Black Mountain
Dry Weather
Detection Program

Purpose
The purpose of this procedure is to define the methods and procedures to monitor and collect dry
weather flow data in the Town of Black Mountain.
Scope
The procedures included herein apply to inspection Town of Black Mountain stormwater outfalls
in the Town's MS4 permit and any future updates or provisions required by the State of North
Carolina and/or the Environmental Protection Agency.
Prioritization Process
The Town has more than 125 town -owned outfalls within its jurisdiction. Through a
prioritization process, the Town has identified 20 of outfalls that will have monitoring activity
take place at least once per year, with a goal of twice per year. The remaining outfalls will be
monitored divided into even and odd year inspection schedules. The prioritized outfalls were
identified using the following considerations:
Land use type: Any outfalls with portions of the drainage area with industrial land uses
Age of Infrastructure: If the age of the infrastructure is known, and is older than
compared to other existing stormwater infrastructure
• Development Intensity: Areas with significant construction and increasing development
activity
Staff
Field inspections of municipal outfalls are to be conducted by public works staff or the building
official until which time the Town of Black Mountain funds and hires dedicated stormwater
staff. Findings are to be provided to the Planning Director for data collection, monitoring,
compliance reporting and testing as required.
NOTE:
In the FY 20-21 budget separate funds for contract services to conduct dry weather
monitoring is included, there is also the potential the town will instead hire a full time
stormwater field technition who will implement this effort and report to the planning
director.
Field Procedures
Dry weather monitoring will occur only after a dry period of at least 72 hours. The screening
activities will be completed during the dry season, specifically during the months July, August
and September.
1. Staff conducting dry weather monitoring shall have the following equipment:
0 MS4 Outfall Map

• Inspection list
• Map with potential IDDE sources identified
• Proper attire, including boots, gloves, safety vest
• Camera
• Sample bottles with labels
• Permeant marker
2. Inspection Methodology
• Preparation
o Review map and outfalls to be inspected
o Review materials and supplies for necessary inspections
o Notify Planning Director if additional supplies are needed
• Safety Considerations
o Work in pairs
o Watch for traffic
o Be aware of poison ivy, snakes and other natural hazards
o Stay hydrated
o Be aware of uneven terrain
o Carry phone or radio
• Complete Inspection Form
o Complete an inspection form (provided by Planning Director)
o Take a photo only if there is a flow present
o Collect the sample for field and potentially laboratory analysis
o Label the bottle with the outfall number, date and time of collection.
o Following the procedures on the inspection form to describe available details and
characterization of the flow
o Provide inspection forms, checklist of inspected outfalls, photos and inspection
sheets to the Planning Director.