10 AM w/ Phil Allen ###-####

BMPs installed per site plan and correctly including:
- construction entrance
- storm drain inlet protection in parking lot (2), and 1 on Overland, 1 on Five Mile
traffic plan with a one way flow
- secondary containment for portapots
- perimeter features preserved along both roads, including a silt fence. Some trees along ROW to remain, ones within the parking lot to be removed.
- will use ecopan for washout
- workers will park offsite to prevent trackout
- permit sign will be posted at entrance

Approved for construction




Need to change RP to Phil Allen.

Rainfall event inspection 12 - 3 PM continued from AM inspection. Raining most of the day with runoff continuing to flow onsite and on surrounding streets

- inspected upper area, no berm blowouts or perimeter breaches observed
- Source of muddy runoff the road mix prepped for paving and that the storm drain pipe down Vortex is not complete.
- Sand bags installed to minimize muddy water leaving at Trent Point have reduced flow offsite.
- Syman onsite inspecting and taking turbidity samples which are entered in SWPPP



Turbidity testing @ 1:30 PM

Background stormwater turbidity going into pond:
- inlet pipe to pond 206 NTU
- gutter at Ridgepoint and Stone Ridge 102 NTU

Outfall and stream at bottom of site:
- In pipe from pond 157 NTU
- in pipe from lower Mesa streets 29 NTU
....
turbidity and flow suddenly increased during testing. Rip-rap splashing water onto the unstabilized dirt around outlet pipes and eroding soil. Sample at bottom of rip rap 552 NTU

Discovered source of surge of muddy water was the ball valve in outlet pipe from detention dam failed. Muddy water that had been detained onsite discharged. RP Steve and L2 crew were able to cap the outlet pipe in the pond to stop discharge. Pond was uncapped for approx. 2 hours

Turbidity samples at bottom of hill on channels leading towards river:
2:25 PM ACHD stormwater channel 87.4 NTU
2:30 PM outfall to wetland river channel 74.3 NTU
2:35 PM in stream just above Warm Springs Road 796 NTU

Correction requests:
- park asphalt mixer within site, not on street entrance. Water pooling in asphalt bin and leaking out, slight sheen observed
- clean up spill/sheen near asphalt machine (could be from Suez/Granite job as well)
- inspect site tomorrow for issues and turbidity testing
- need to stabilze/cover the dam face within 10 ft radius around the two outfall pipes to prevent splash back from rip rap and erosion in this area
- clean up any loose dirt on Ridgepoint around storm drain to pond
- file corrective action report in SWPPP
- once stream no longer has flow, need to inspect and clean up mud accumulations

notify ACHD about the roadway runoff issue