post rainfall inspection

Monday 6/15 turbidity testing:

- background into vortex/Ridgepoint pond: 49.8 NTU
- Vortex/Ridgepoint pond outfall manhole: 81.5 NTU
- Site stormwater outfall to stream: 78.8 NTU
- Downstream below riprap: 71.6 NTU. The discharge at time of inspection was with water qualtiy limit and in compliance.

Observations:

- the corrective action taken by site to clean out all manholes and stormwater bypass system seems to have eliminated the issue of water entering the pipe from the pond and then stirring up deposited mud/sediment in each manhole junction.

- no significant issues observed in upper section of subdivision. Good vegetation, streets paved, silt fence and vegetated buffer perimeter
- stormwater running down Ridgepoint into the pond comes at too great of velocity and volume for the existing riprap spillway in front on the storm drain drop inlets. Erosion occurs on the spillway into the pond
- rilling has started to occur on the dam face and wattle maintenance is needed. No sign of any of the recent seeding application growing. Lots of dirt and mud has been deposited into the center rip rap. No sediment control at bottom end of dam above outfalls.
- Syman onsite for turbiditiy testing and results put in SWPPP
- dewatering out of plugged resevoir into upland vegetation has been approved. Request to place pump hose on pontoon to get top of water column, putting energy dissipation at hose outlet and direct water down existing draw. Did not request to attach silt bag at end of hose in worry of plugging and malfunction.

Correction request:
- schedule wattle mainteance and installation on dam. Apply temporary tacifier or re-seed with mulch.

Roofing crew parked on street. No trackout, no significant sediment runoff.