BEsT MANAGEMENT PRACTICEs HANDbooK - Tahoe BMP

to perform required inspection and maintenance activities. Refer to Chapter 6Inspection, Maintenance, and Monitoring for detailed requirements andguidance for creating a project specific plan.Lake Tahoe Region jurisdictions use Lake Tahoe TMDL tools including a BMPRAM and a Road RAM to assess relative conditions of BMPs and roadwayswithin the public right-of-way. These tools assist local jurisdiction staff toprioritize and target maintenance activities on a regular basis to maintainpollutant load reduction targets set forth in the Lake Tahoe TMDL.3.8 SITE CONSTRAINTS AND LIMITATIONSRetrofitting or redeveloping existing properties can bring difficult designchallenges. Obstacles may hinder design progress and, in some cases, potentialsolutions may be cost prohibitive.3.8.1 SPECIAL CIRCUMSTANCES IF INFILTRATION IS NOT FEASIBLEIf infiltration is not feasible due to site constraints, as defined and determinedby TRPA, then special circumstances may apply. A list of potential siteconstraints is discussed below. In the event that site conditions do not provideopportunities to infiltrate the runoff volume generated by a 20-yr/1-hr storm,project proponents must do either of the following:• “Treat and Release” of Stormwater to Surface WatersTreat stormwater to meet TRPA discharge standards outlined in Section 60.1.3of the TRPA Code of Ordinances using proprietary or publicly availabletechnologies and establish a legal agreement with the local jurisdiction oranother property owner to allow stormwater to discharge offsite. Proprietary“treat and release” media filtration technology may be an appropriate option inareas with infiltration site constraints.• Coordination with Local jurisdictionsCoordinate with the local municipality or state highway department todocument that shared stormwater treatment facilities treating private propertydischarges and public right-of-way stormwater sufficiently contribute tomeeting the jurisdictions’ pollutant load reduction requirements.3.8.2 COMMON SITE CONSTRAINTS AND ASSOCIATED BMP DESIGN CONCEPTSSite constraints are defined as physical land attributes that prevent, orcontribute to difficulties in, the implementation of BMPs required to meetregulatory water quality standards. The following are general suggestions foraddressing commonly occurring site limitations and constraints. While theseBMP design concepts may assist a project designer or planner in findingsolutions to site constraints, each site has a unique set of issues andcharacteristics that need to be assessed individually to find the most appropriatesolution.Stormwater In-LieuAssessmentsWhere permitted and legallyestablished by a localjurisdiction, a private parcelowner may at times providean easement or cashcontribution toward a publicproject in-lieu of installing theirinfiltration BMPs. Thisexchange is determined on anindividual, project, orjurisdiction-wide basis. A localjurisdiction may choose toaccept runoff from privateparcels and enter into legalagreements or assess parcelsthrough local ordinances.Sediment and erosion controland pollutant source controlmeasures are still required onall private properties regardlessif they are part of an in-lieustormwater fee or assessmentdistrict.TRPA requires at least 1 foot ofseparation from the bottom ofinfiltration systems to seasonalhigh groundwater soilindicators. This distance mayincrease or decreasedependent upon the projectsite and the discretion of thepermitting authority.TRPA BMP HandbookCHAPTER 3: Permanent BMP Planning and Selection2012 Page 3-29